Copper-based catalyst precursor, method for manufacturing same, and hydrogenation method

ABSTRACT

A copper-based catalyst precursor capable of achieving a high conversion ratio and high selectivity in the isomerization reaction of a β,γ-unsaturated alcohol portion and a method for producing the same and to provide a hydrogenation method in which the copper-based catalyst precursor is used are provided. Specifically, a copper-based catalyst precursor obtained by calcining a mixture containing copper, iron, aluminum, and calcium silicate in which an atomic ratio of iron and aluminum to copper [(Fe+Al)/Cu] is in a range of 1.71 to 2.5, an atomic ratio of aluminum to iron [Al/Fe] is in a range of 0.001 to 3.3, and calcium silicate is contained in a range of 15% by mass to 65% by mass at a temperature in a range of 500° C. to 1,000° C. and a hydrogenation method in which the copper-based catalyst precursor is used are provided.

TECHNICAL FIELD

The present invention relates to a copper-based catalyst precursor, amethod for producing the same, and a hydrogenation method. In moredetail, the present invention relates to a copper-based catalystprecursor containing copper, iron, aluminum, and the like, a method forproducing the same, and a hydrogenation method in which the copper-basedcatalyst precursor is used. Furthermore, the present invention alsorelates to a copper-based catalyst obtained by reducing the copper-basedcatalyst precursor.

BACKGROUND ART

As a method for obtaining an aldehyde compound by isomerizing aβ,γ-unsaturated alcohol portion, for example, an isomerization reactionof 7-octenal from 2,7-octadiene-1-ol is known. It has been reportedthat, in the isomerization reaction, the use of a copper-based catalystprecursor containing copper, iron, and aluminum enables the selectiveproduction of target substances (refer to PTL 1 to 3).

As a method for producing the copper-based catalyst precursor containingcopper, iron, and aluminum, a method in which an aqueous solution ofmixed metal salts including a water-soluble copper salt, a water-solubleiron salt, and a water-soluble aluminum salt as main components with abasic aqueous solution as a precipitant are reacted together so as toobtain a coprecipitate containing copper, iron, and aluminum, thecoprecipitate is filtered, then, washed with water, dried, and calcinedis known (refer to PTL 4 and 5).

When the coprecipitate containing copper, iron, and aluminum is calcinedat a temperature in a range of 600° C. to 1,000° C., a spinel structureis formed. It is known that the atomic ratio between copper, iron, andaluminum in the coprecipitate is a factor that changes thedispersibility and the like of copper in the spinel structure, andfurthermore, changes the activity and selectivity of the copper-basedcatalyst (refer to PTL 4 to 8).

It is also known that, in a case in which a copper-based catalystprecursor containing copper, iron, and aluminum which is obtained bycoprecipitating a copper compound, an iron compound, and an aluminumcompound on the surface of a carrier, and calcining the coprecipitate at750° C. is used in a hydrogenation reaction, the activity andselectivity of the copper-based catalyst are changed depending on thekind of the carrier (PTL 9). That is, it is known that the atomic ratiobetween copper, iron, and aluminum in the coprecipitate, the kind andcontent of the carrier included in the coprecipitate, and thecalcination temperature for turning the coprecipitate into thecopper-based catalyst precursor change the activity and selectivity ofthe copper-based catalyst.

When the coprecipitate containing copper, iron, and aluminum is dried ata temperature in a range of 100° C. to 150° C., and then calcined at atemperature in a range of 600° C. to 1,000° C., a copper-based catalystprecursor can be obtained. Furthermore, when the copper-based catalystprecursor is hydrogen-reduced, the precursor becomes activated, and thencan be used in desired reactions as a copper-based catalyst.Alternatively, it is also possible to crush the precursor after thecalcining, activate the obtained powder-form copper-based catalystprecursor through hydrogen reduction, and use the powder in reactions asa powder-form copper-based catalyst. When it is also possible to use thecalcined powder-form copper-based catalyst precursor formed throughcompression, extrusion, or the like as desired, it is also possible touse the dried coprecipitate that is formed through compression,extrusion, or the like, and then is calcined (refer to PLT 5, 12, andthe like).

It is known that the copper-based catalyst precursor containing copper,iron, and aluminum can be used in a variety of hydrogenation reactionssuch as hydrogenation from an aliphatic ester compound to a higheralcohol (refer to PLT 4 to 12).

CITATION LIST Patent Literature

[PTL 1] JP-A-02-218638

[PTL 2] JP-A-11-171814

[PTL 3] JP-A-20-247865

[PTL 4] JP-A-53-92395

[PTL 5] JP-A-55-8820

[PTL 6] JP-A-55-129151

[PTL 7] JP-A-2-251245

[PTL 8] JP-A-4-22437

[PTL 9] JP-A-5-31366

[PTL 10] JP-A-5-168931

[PTL 11] JP-A-9-276699

[PTL 12] JP-A-6-226100

SUMMARY OF INVENTION Technical Problem

The present inventors prepared a copper-based catalyst through thehydrogen reduction of a copper-based catalyst precursor obtained byadding γ-alumina as a carrier, which is described to be preferable inPLT 11, to a coprecipitate containing copper, iron, and aluminum,washing the mixture, drying the obtained coprecipitate at 120° C., andthen calcining the coprecipitate at an arbitrary temperature in a rangeof 120° C. to 800° C. As a result of using the copper-based catalyst inan isomerization reaction of 2,7-octadiene-1-ol to 7-octenal, it wasfound that, while the conversion ratio improved as the calcinationtemperature increased, the conversion ratio was still low andunsatisfactory, and furthermore, the selectivity was also low. In theisomerization reaction of 2,7-octadiene-1-ol to 7-octenal, particularly,it is difficult to separate the target substance of 7-octenal and abyproduct of 2,7-octadienal. As a result, there has been a desperatedesire for the development of a copper-based catalyst capable ofobtaining a high conversion ratio and increasing the selectivity of7-octenal, even by a slight amount. In addition, it can be said that thecopper-based catalyst is also useful as a hydrogenation catalyst capableof hydrogenating a carbon-carbon double bond or a carbon-oxygen doublebond, and particularly, 1-octanol which is useful as a resin plasticizercan be produced using the hydrogenation reaction of 7-octenal.

Therefore, an object of the present invention is to provide acopper-based catalyst precursor capable of achieving a high conversionratio and high selectivity in the isomerization reaction of aβ,γ-unsaturated alcohol portion and a method for producing the same andto provide a hydrogenation method in which the copper-based catalystprecursor is used.

Solution to Problem

As a result of intensive studies, the present inventors found that acopper-based catalyst obtained from a copper-based catalyst precursor byadding calcium silicate to a coprecipitate containing copper, iron, andaluminum in which copper, iron, and aluminum have a relationship of aspecific atomic ratio, filtering the obtained coprecipitate, and thencalcining the coprecipitate at 800° C. improves the conversion ratio andthe selectivity of 7-octenal in the isomerization reaction of2,7-octadiene-1-ol to 7-octenal. It was found that this performancecannot be achieved only by optimizing the atomic ratio between copper,iron, and aluminum or the calcination temperature or only by usingcalcium silicate, but can be achieved by combining the options of theatomic ratio or the calcination temperature and the use of calciumsilicate. Furthermore, it was found that the copper-based catalyst canalso be used in the hydrogenation reaction of 1-octanol from 7-octenal.

In addition, it was found that, according to the production method, adecrease in the filtration rate during the filtration of acoprecipitated mixture, which is described in PTL 6 to 8, is notobserved, and the production method is an industrially easy productionmethod.

The present invention has been completed on the basis of theabove-described findings.

That is, the present invention relates to the following [1] to [15].

[1] A copper-based catalyst precursor obtained by calcining a mixturecontaining copper, iron, aluminum, and calcium silicate in which anatomic ratio of iron and aluminum to copper [(Fe+Al)/Cu] is in a rangeof 1.71 to 2.5, an atomic ratio of aluminum to iron [Al/Fe] is in arange of 0.001 to 3.3, and calcium silicate is contained in a range of15% by mass to 65% by mass at a temperature in a range of 500° C. to1,000° C.

[2] The copper-based catalyst precursor according to [1], in which themixture is a dried product of a coprecipitated mixture obtained bymixing a coprecipitate and calcium silicate, which coprecipitate isobtained by reacting a mixed aqueous solution including a water-solublecopper salt, a water-soluble iron salt, and a water-soluble aluminumsalt with a basic aqueous solution.

[3] The copper-based catalyst precursor according to [1] or [2], inwhich, in the calcium silicate, an atomic ratio of silicon to calcium[Si/Ca] is in a range of 0.5 to 6.5.

[4] The copper-based catalyst precursor according to any one of [2] or[3], in which a BET specific surface area of the mixture is in a rangeof 50 m²/g to 250 m²/g.

[5] The copper-based catalyst precursor according to any one of [1] to[4], in which the calcium silicate is a Gyrolite-type synthetic calciumsilicate represented by 2CaO.3SiO₂.mSiO₂.nH₂O (m and n, respectively,are numbers satisfying 1<m<2 and 2<n<3).

[6] The copper-based catalyst precursor according to [5], in which abulk specific volume of the calcium silicate is 4 mL/g or more.

[7] A copper-based catalyst obtained by reducing the copper-basedcatalyst precursor according to any one of [1] to [6].

[8] A method for producing the copper-based catalyst precursor accordingto any one of [1] to [6], including:

first step: a step for generating a coprecipitate containing copper,iron, and aluminum by reacting a mixed aqueous solution including awater-soluble copper salt, a water-soluble iron salt, and awater-soluble aluminum salt with a basic aqueous solution;

second step: a step for obtaining a coprecipitated mixture by addingcalcium silicate to a suspension including the coprecipitate obtained inthe first step suspended in water and mixing the components together;

third step: a step for obtaining the dried product of the coprecipitatedmixture by separating the coprecipitated mixture obtained in the secondstep, washing the coprecipitated mixture with water, and then drying thecoprecipitated mixture; and

fourth step: a step for calcining the dried product of thecoprecipitated mixture obtained in the third step at a temperature in arange of 500° C. to 1,000° C.

[9] The method for producing the copper-based catalyst precursoraccording to [8], in which, in the first step, a reaction temperature isin a range of 5° C. to 150° C., and a pH of the aqueous solution is in arange of 6.0 to 13.5, and in the second step, a temperature of thesuspension to which calcium silicate is added is in a range of 5° C. to100° C., and a pH of the suspension is in a range of 7 to 9.

[10] The method for producing the copper-based catalyst precursoraccording to [8] or [9], in which, in the first step, the water-solublecopper salt is copper (II) sulfate, the water-soluble iron salt is iron(I) sulfate, and the water-soluble aluminum salt is aluminum sulfate.

[11] The method for producing the copper-based catalyst precursoraccording to any one of [8] to [10], in which a calcination temperaturein the fourth step is in a range of 600° C. to 900° C.

[12] A hydrogenation method of a compound having either or both acarbon-carbon double bond and a carbon-oxygen double bond, in which thecopper-based catalyst precursor according to any one of [1] to [6] isused.

[13] The hydrogenation method according to [12], in which thehydrogenation method is carried out at a temperature in a range of 100°C. to 300° C. and at a total pressure in a range of 0.01 MPa(G) to 30MPa(G).

[14] The hydrogenation method according to [12] or [13], in which thehydrogenation method is carried out using a slurry-bed reaction method.

[15] The hydrogenation method according to any one of [12] to [14], inwhich the compound having either or both a carbon-carbon double bond anda carbon-oxygen double bond is selected from a group consisting ofaldehydes which may include a carbon-carbon double bond, ketones whichmay include a carbon-carbon double bond, carboxylic acids which mayinclude a carbon-carbon double bond, esters which may include acarbon-carbon double bond, acid anhydrides which may include acarbon-carbon double bond, and sugars which may include a carbon-carbondouble bond.

Advantageous Effects of Invention

The copper-based catalyst obtained by hydrogen-reducing the copper-basedcatalyst precursor of the present invention is capable of achieving ahigh conversion ratio and high selectivity in the isomerization of aβ,γ-unsaturated alcohol portion. Furthermore, the copper-based catalystobtained from the copper-based catalyst precursor can also be used forthe hydrogenation of a carbon-carbon double bond, a carbon-oxygen doublebond, and the like.

In addition, according to the production method of the presentinvention, it is possible to produce the copper-based catalyst precursorin an easy industrial manner.

DESCRIPTION OF EMBODIMENTS

[Copper-Based Catalyst Precursor]

The present invention is a copper-based catalyst precursor obtained bycalcining a mixture containing copper, iron, aluminum, and calciumsilicate in which the atomic ratio of iron and aluminum to copper[(Fe+Al)/Cu] is in a range of 1.71 to 2.5, the atomic ratio of aluminumto iron [Al/Fe] is in a range of 0.001 to 3.3, and calcium silicate iscontained in a range of 15% by mass to 65% by mass at a temperature in arange of 500° C. to 1,000° C.

In a case in which the atomic ratio of iron and aluminum to copper isless than 1.71, the diameters of copper crystals in the copper-basedcatalyst are increased, and a decrease in the catalyst activity per unitmass of copper, a decrease in the selectivity into the target substancecaused by the large diameter of metal crystals, and a decrease in thecatalyst activity over time due to the growth of metallic coppercrystals are caused. On the other hand, in a case in which the atomicratio of iron and aluminum to copper exceeds 2.5, the content of copperincluded per unit mass of the copper-based catalyst is decreased, andthus a desired catalyst activity cannot be achieved. Meanwhile, in acase in which the atomic ratio of aluminum to iron exceeds 3.3, theconversion ratio and the selectivity are decreased in the isomerizationreaction of a compound having a β,γ-unsaturated alcohol portion to analdehyde compound.

From the above-described viewpoint, [(Fe+Al)/Cu] is preferably in arange of 1.80 to 2.50, more preferably in a range of 1.90 to 2.5, stillmore preferably in a range of 1.90 to 2.4, and particularly preferablyin a range of 2.1 to 2.21. In addition, from the above-describedviewpoint, [Al/Fe] is preferably in a range of 0.001 to 3.2, morepreferably in a range of 0.001 to 3.0, still more preferably in a rangeof 0.005 to 2.9, and particularly preferably in a range of 0.20 to 0.45.

A method for producing the copper-based catalyst precursor of thepresent invention will be described below.

As a method for producing the mixture, the following methods can beused.

(a) A method in which a coprecipitate obtained by reacting a mixedaqueous solution including a water-soluble copper salt, a water-solubleiron salt, and a water-soluble aluminum salt with a basic aqueoussolution is mixed with calcium silicate. A method in which a suspensionincluding the coprecipitate suspended in water and calcium silicate aremixed together is preferred.

(b) A method in which a coprecipitate is generated by reacting a mixedaqueous solution including a water-soluble copper salt, a water-solubleiron salt, and a water-soluble aluminum salt with a basic aqueoussolution, the separated coprecipitate is dried, calcium silicate isadded to the coprecipitate, and calcium silicate and the coprecipitateare mixed together in solid phases.

(c) A method in which a coprecipitate is generated by reacting a mixedaqueous solution including one or two selected from a water-solublecopper salt, a water-soluble iron salt, and a water-soluble aluminumsalt with a basic aqueous solution, the coprecipitate, oxides orhydroxides of metals selected from copper, iron, and aluminum (themetals are selected so that three metals of copper, iron, and aluminumare all present in the mixture), and calcium silicate are mixedtogether, and the mixture is isolated and dried.

(d) A method in which oxides or hydroxides of metals of copper, iron,and aluminum and calcium silicate are mixed together in solid phases orliquid phases.

In any of the methods, other components may be further mixed in, andmetals other than copper, iron, and aluminum may be included in themixture.

The mixture or coprecipitated mixture obtained in the above-describedmanner is separated, and then dried, thereby obtaining the dried productof the coprecipitated mixture.

From the viewpoint of the uniform mixing of copper, iron, and aluminumand productivity, the method (a) is preferably employed. As copper,iron, and aluminum are more uniformly mixed together, it is possible toachieve the desired selectivity and activity of the copper-basedcatalyst with favorable reproducibility.

The copper-based catalyst precursor of the present invention is morepreferably produced using a production method including first to fourthsteps described below.

First step: a step for generating a coprecipitate containing copper,iron, and aluminum by reacting a mixed aqueous solution including awater-soluble copper salt, a water-soluble iron salt, and awater-soluble aluminum salt with a basic aqueous solution.

Second step: a step for obtaining a coprecipitated mixture by addingcalcium silicate to a suspension including the coprecipitate obtained inthe first step suspended in water and mixing the components together.

Third step: a step for obtaining the dried product of the coprecipitatedmixture by separating the coprecipitated mixture obtained in the secondstep, washing the coprecipitated mixture with water, and then drying thecoprecipitated mixture.

Fourth step: a step for calcining the dried product of thecoprecipitated mixture obtained in the third step at a temperature in arange of 500° C. to 1,000° C.

Hereinafter, the respective steps will be sequentially described indetail.

(First Step)

The first step is a step for generating a coprecipitate containingcopper, iron, and aluminum by reacting a mixed aqueous solutionincluding a water-soluble copper salt, a water-soluble iron salt, and awater-soluble aluminum salt with a basic aqueous solution.

In the coprecipitate obtained in the first step, the atomic ratio ofiron and aluminum to copper [(Fe+Al)/Cu] is preferably in a range of1.71 to 2.5, and the atomic ratio of aluminum to iron [Al/Fe] ispreferably in a range of 0.001 to 3.3. With the atomic ratios in theabove-described ranges, it is possible to obtain the target copper-basedcatalyst precursor.

In the coprecipitate, [(Fe+Al)/Cu] is preferably in a range of 1.80 to2.50, more preferably in a range of 1.90 to 2.5, still more preferablyin a range of 1.90 to 2.4, and particularly preferably in a range of 2.1to 2.21. In addition, [Al/Fe] is preferably in a range of 0.001 to 3.2,more preferably in a range of 0.001 to 3.0, still more preferably in arange of 0.005 to 2.9, and particularly preferably in a range of 0.20 to0.45.

Meanwhile, regarding [(Fe+Al)/Cu] and [Al/Fe], it is possible toarbitrarily combine the above-described ranges.

Examples of the water-soluble copper salt include hydrosulfate, hydrogensulfate, nitrate, carbonates, hydrogen carbonates, organic acid salts,chlorides, and the like of copper. More specific examples thereofinclude copper (II) sulfate, copper (II) nitrate, copper (II) chloride,and the like. The water-soluble copper salt may be singly used, or twoor more water-soluble copper salts may be jointly used. From theviewpoint of easy procurement and price, copper (II) sulfate ispreferred.

Examples of the water-soluble iron salt include hydrosulfate, hydrogensulfate, nitrate, carbonates, hydrogen carbonates, organic acid salts,chlorides, and the like of iron. More specific examples thereof includeiron (I) sulfate, iron (I) nitrate, iron (I) chloride, and the like. Thewater-soluble iron salt may be singly used, or two or more water-solubleiron salts may be jointly used. From the viewpoint of easy procurementand price, iron (I) sulfate is preferred.

Examples of the water-soluble aluminum salt include acetate, nitrate,hydrosulfate, and the like of aluminum. More specific examples thereofinclude sodium aluminate, aluminum sulfate, aluminum chloride, aluminumnitrate, and the like. The water-soluble aluminum salt may be singlyused, or two or more water-soluble aluminum salts may be jointly used.From the viewpoint of easy procurement and price, aluminum sulfate ispreferred.

The water-soluble copper salt, the water-soluble iron salt, and thewater-soluble aluminum salt may contain a free acid that does not form acomplex with metal, or may be a hydrate.

From the viewpoint of producing the homogeneous coprecipitate, anaqueous solution of the water-soluble copper salt, the water-solubleiron salt, and the water-soluble aluminum salt (hereinafter, in somecases, will be collectively referred to as metal salts) preferablyincludes no insoluble matter, and it is preferable to prepare a uniformsolution through filtration if necessary.

There is no particular limitation regarding the concentration of theaqueous solution of the metal salts, but the concentration of the metalsalts is preferably in a range of 5% by mass to 35% by mass, and morepreferably in a range of 10% by mass to 25% by mass. When theconcentration is 35% by mass or lower, it is difficult for aheterogeneous coprecipitate to be generated during the reaction with thebasic aqueous solution. On the other hand, when the concentration is 5%by mass or higher, the volume efficiency is sufficient, and theproduction cost of the copper-based catalyst precursor can be reduced.

In a case in which the metal salts contain a free acid, theconcentrations of the free acid included in the respective metal saltsare all preferably in a range of 0.05% by mass to 20% by mass, and morepreferably in a range of 0.1% by mass to 10% by mass. In the case of themetal salts containing 0.05% by mass or higher of the free acid, it isnot necessary to purify the metal salts through crystallization in orderto remove the free acid, and the production cost of the metal salts canbe reduced. In addition, in a case in which the concentration of thefree acid is 20% by mass or lower, a basic substance for neutralizingthe free acid is not required, and there is no concern of catalystperformance being degraded by the interfusion of neutral salts producedfrom the free acid and the basic substance into the coprecipitate.

Examples of the basic substance for preparing the basic aqueous solutioninclude hydroxides of alkali metals, hydroxides of alkali earth metals,carbonates of alkali metals, carbonates of alkali earth metals, hydrogencarbonates of alkali metals, hydrogen carbonates of alkali earth metals,and the like. More specific examples thereof include lithium hydroxide,sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, and the like. As the basic substance, additionally, aninorganic base such as ammonia or an organic base such as urea orammonium carbonate can also be used.

The basic substance may be singly used, or two or more basic substancesmay be jointly used. From the viewpoint of easy procurement and price,sodium hydroxide is preferred.

The reaction temperature is preferably in a range of 5° C. to 150° C.,and more preferably in a range of 60° C. to 100° C. When the reactiontemperature is 5° C. or higher, the time taken to neutralize the freeacid becomes short, and there is no concern of catalyst performancebeing degraded by the interfusion of alkali metal salts of acids and thelike into the coprecipitate. In addition, when the reaction temperatureis 150° C. or lower, a pressure-resistant container or the like isunnecessary, which is economically preferred.

Examples of a chemical mixing procedure for reacting an aqueous solutionincluding the water-soluble copper salt, the water-soluble iron salt,and the water-soluble aluminum salt and the basic aqueous solutioninclude (1) a method in which a variety of aqueous solutions of metalsalts are added to the basic aqueous solution, (2) a method in which thebasic aqueous solution is added to a variety of aqueous solutions ofmetal salts, and the like. From the viewpoint of controlling thereaction system to be basic, the method (1) is preferred.

The pH inside the reaction system is preferably in a range of 6.0 to13.5, and more preferably in a range of 7.0 to 9.0. When the pH insidethe reaction system is 6.0 or more, there are no cases in which thehomogeneity of the coprecipitate is impaired by the re-dissolution ofthe copper component, and catalyst performance is not degraded. Inaddition, when the pH is 13.5 or less, there are no cases in whichneutral salts generated from the basic substance interfuse into thecoprecipitate, and there is no concern of catalyst performance beingdegraded.

When the coprecipitate having desired Cu/Fe/Al atomic ratios, that is,desired [(Fe+Al)/Cu] and desired [Al/Fe] is produced, it is preferableto prepare in advance a mixed aqueous solution obtained by mixing(preferably uniformly mixing) the water-soluble copper salt, thewater-soluble iron salt, and the water-soluble aluminum salt so thatdesired metal atomic ratios are obtained, and add the mixed aqueoussolution to the basic aqueous solution from the viewpoint of producingthe homogeneous coprecipitate. For example, when the aluminum salt andthe basic aqueous solution are reacted together, and then the coppersalt, the iron salt, and the basic aqueous solution are reactedtogether, there are cases in which copper hydroxide and iron hydroxideaccumulate using aluminum hydroxide as a nucleus, and thus aheterogeneous coprecipitate can be obtained. In a case in which theheterogeneous coprecipitate is calcined, a spinel structure made up ofcopper and iron is formed, and thus desired catalyst performance cannotbe achieved.

The mixed aqueous solution prepared in the above-described manner ispreferably added, that is, added gently dropwise to the basic aqueoussolution. The dropwise addition time is preferably in a range of 30minutes to 360 minutes, and more preferably in a range of 60 minutes to240 minutes. When the dropwise addition time is 30 minutes or longer,the mixed aqueous solution is sufficiently stirred and mixed with thebasic aqueous solution, and thus there are no cases in which temperaturecontrol becomes difficult due to reaction heat, and a heterogeneouscoprecipitate is not easily generated. In addition, when the dropwiseaddition time is 360 minutes or shorter, the volume efficiency issufficient, and the production cost of the copper-based catalystprecursor can be reduced.

There is no particular limitation regarding the state inside thereaction system; however, generally, a state in which a coprecipitatebeing generated does not settle, and is dispersed in the system ispreferred. In a state in which the coprecipitate does not settle, aheterogeneous coprecipitate is not generated, and thus the performanceof the copper-based catalyst improves.

In addition, it is normal to allow an aging time until the reaction iscompleted after the mixed aqueous solution is added dropwise to thebasic aqueous solution, which is preferable. Generally, the aging timeis preferably in a range of 1 hour to 10 hours. Meanwhile, the change inthe pH of a suspension of the coprecipitate during aging is preferablyless than 0.3 per hour.

While it is also possible to obtain the coprecipitated mixture bydirectly adding calcium silicate to the suspension including thecoprecipitate obtained in the above-described manner, and then filteringthe mixture, from the viewpoint of avoiding the interfusion of neutralsalts into the coprecipitate, it is preferable to wash thecoprecipitate, and then proceed to the second step described below. Morespecifically, it is preferable to obtain the coprecipitate afterrepeating an operation in which the suspension including thecoprecipitate is left to stand at a temperature preferably in a range of5° C. to 100° C., more preferably in a range of 10° C. to 80° C., andstill more preferably in a range of 30° C. to 70° C., supernatant isremoved using the decantation method, and then ion exchange water isadded until the pH of the supernatant falls in a range of 7 to 9.

(Second Step)

The second step is a step for obtaining a coprecipitated mixture byadding calcium silicate to the suspension including the coprecipitateobtained in the first step suspended in water and mixing the componentstogether.

As the suspension including the coprecipitate suspended in water, asdescribed above, the suspension of the coprecipitate obtainedimmediately after the reaction in the first step may be used without anychanges, or a suspension obtained by washing the coprecipitate obtainedimmediately after the reaction in the first step, and then adding watermay be used. The pH of the suspension is preferably in a range of 7.0 to9.0, and more preferably in a range of 7.0 to 8.0.

The temperature at which the suspension and calcium silicate are mixedtogether is preferably in a range of 5° C. to 100° C., more preferablyin a range of 10° C. to 80° C., and still more preferably in a range of30° C. to 70° C. In addition, the suspension and calcium silicate arepreferably mixed in a state in which the suspension and calcium silicateare stirred so that the coprecipitate does not settle and accumulate.

In the calcium silicate being added, the atomic ratio of silicon tocalcium [Si/Ca] is preferably in a range of 0.5 to 6.5, more preferablyin a range of 1.6 to 4.0, and still more preferably in a range of 2.3 to3.7. Meanwhile, an amount of calcium silicate is preferably added sothat the content of calcium silicate included in the dried product ofthe mixture obtained in the third step described below falls in a rangeof 15% by mass to 65% by mass (more preferably in a range of 20% by massto 55% by mass). When the content is 15% by mass or more, the filtrationspeed of the coprecipitated mixture made up of the coprecipitate andcalcium silicate is sufficiently fast. In addition, when the content is65% by mass or less, it is possible to maintain the content of copper inthe copper-based catalyst at a high level, and there is no concern ofcatalyst activity being degraded.

Examples of calcium silicate used in the present invention includexonotite, tobermorite, gyrolite, foshagite, hillebrandite, and the like,and calcium silicate can be used in a form made up of one or morethereof. From the viewpoint of facilitating the quality stabilization ofthe copper-based catalyst precursor of the present invention, a chemicalsynthetic product is preferred.

From the viewpoint of an increase in the filtration speed, theimprovement of catalyst formability, and an increase in the dynamicstrength of a forming catalyst, particularly, synthetic calcium silicatebelonging to a Gyrolite-type calcium silicate is preferably used, and apetal-shaped synthetic calcium silicate belonging to Gyrolite-typecalcium silicates is more preferably used.

A method for producing the petal-shaped calcium silicate is described inJP-B-60-29643. That is, the petal-shaped calcium silicate can beobtained by reacting an aqueous silicate (for example, sodium silicate)and a water-soluble calcium salt (for example, calcium chloride)together at a temperature in a range of 150° C. to 250° C. underconditions in which the content of a solvent falls in a range of 5 partsby mass to 100 parts by mass of the obtained calcium silicate. In thepetal-shaped calcium silicate that can be obtained in theabove-described manner, the atomic ratio [Si/Ca] is generally in a rangeof 1.6 to 6.5, the bulk specific volume is 4 mL/g or more, the oilabsorption amount is 2.0 mL/g or more, and the refractive index is in arange of 1.46 to 1.54.

In more detail, for example, an aqueous solution of sodium silicate andan aqueous solution of calcium chloride are mixed together at roomtemperature at the atmospheric pressure so that the atomic ratio [Si/Ca]reaches approximately 2.6, the mixture is introduced into an autoclaveat a water ratio of 30, the components are reacted together at 200° C.for 5 hours, then, the reactant is filtered, washed with water, anddried, whereby petal-shaped calcium silicate represented by2CaO.3SiO₂.2.20SiO₂.2.30-2.60H₂O can be obtained.

As the petal-shaped calcium silicate, for example, “FLORITE”manufactured by Tomita Pharmaceutical Co., Ltd. is commerciallyavailable. The petal-shaped calcium silicate is generally represented by2CaO.3SiO₂.mSiO₂.nH₂O (m and n, respectively, are numbers satisfying1<m<2 and 2<n<3). The shape of the petal-shaped calcium silicate can beconfirmed through electron microscope observation, and generally, theshape and thickness of the petal shape can be confirmed through electronmicroscope observation at a magnification in a range of 3,000 times to10,000 times. Particularly, from the viewpoint of an increase in theproduction speed of the copper-based catalyst precursor of the presentinvention, the improvement of formability, and an increase in thedynamic strength of a forming catalyst precursor, 5% by mass or more ofcalcium silicate being used is the petal-shaped calcium silicate.

Since the size, shape, and the like of the petal included in thepetal-shaped calcium silicate somewhat differ depending on the kinds ofraw materials used for the production of calcium silicate, the mixingratio of raw materials, and production conditions, the size, shape, andthe like cannot be ordinarily limited; however, generally, a majority ofthe petals have a round shape, an oval shape, or the like having anaverage lengthwise diameter in a range of 0.1 μm to 30 μm and athickness in a range of 0.005 μm to 0.1 μm, and a majority of the petalshave a shape similar to a rose petal. Calcium silicate having an atomicratio [Si/Ca] of less than 1.6 does not have a petal shape, and has atobermorite or xonotite-type crystal form. On the other hand, in calciumsilicate having an atomic ratio [Si/Ca] of more than 6.5, both the bulkspecific volume and the oil absorption amount become small, and there isno growth of petal-shaped calcium silicate observed. Generally, calciumsilicate having an atomic ratio [Si/Ca] of 4.0 or less is most widelyemployed, which is the same as in the present invention.

(Third Step)

The third step is a step for obtaining the dried product of thecoprecipitated mixture by separating the coprecipitated mixture obtainedin the second step, washing the coprecipitated mixture with water, andthen drying the coprecipitated mixture.

For the separation of the coprecipitated mixture obtained in the secondstep, an arbitrary well-known method can be applied; however, from theviewpoint of easy operation, the filtration method is preferablyapplied.

When the filtered substance is washed with distilled water, ion exchangewater, or the like, impurities such as sodium sulfate can be removed.

Any drying methods can be used as long as water can be removed, andgenerally, the coprecipitated mixture is preferably dried at 100° C. orhigher at the atmospheric pressure.

In a case in which there is a desire to extend the service life of thecopper-based catalyst, it is possible to use means for adding inorganicsalts of metals such as zinc, magnesium, barium, sodium, and potassiumto the copper-based catalyst precursor. Generally, the atomic ratio ofthe metals to copper [metals/Cu] is preferably in a range of 0.1 to 3.0.When the atomic ratio is 0.1 or more, desired effects such as theextension of the service life of the copper-based catalyst can bedeveloped. When the atomic ratio is 3.0 or less, there are no cases inwhich the durability of the copper-based catalyst is degraded.

For example, in a case in which at least one selected from magnesium andzinc is added, there is a method in which the aqueous solution of thehydrosulfate thereof is added to the aqueous solution of the metal acidsalts in the first step, thereby obtaining a coprecipitate. In addition,in a case in which at least one selected from barium, sodium, andpotassium is added, there is a method in which the aqueous solution ofthe hydroxide thereof is applied to the coprecipitated mixture separatedin the second step, and then is dried.

The dried product of the coprecipitated mixture obtained in theabove-described manner has a BET specific surface area, which is thenitrogen adsorption specific surface area measured according to“Determination Of The Specific Surface Area Of Powders (Solids) By GasAdsorption Methods” described in JIS Z8830:2001, preferably in a rangeof 50 m2/g to 250 m2/g, more preferably in a range of 100 m2/g to 200m2/g, and still more preferably in a range of 125 m2/g to 175 m2/g. Whenthe BET specific surface area is 50 m2/g or more, an increase in thepore volume of the copper-based catalyst improves the catalyst activity.When the BET specific surface area is 250 m2/g or less, thecoprecipitate and calcium silicate become uniformly mixed together, andthe selectivity in a hydrogenation reaction or an isomerization reactionimproves.

The determination of the atomic ratios of copper, iron, and aluminum andthe determination of the content of calcium silicate in the mixtureincluding copper, iron, aluminum, and calcium silicate, which is used inthe production of the copper-based catalyst precursor of the presentinvention, are the determinations of the dried product of thecoprecipitated mixture obtained in the third step, and are values basedon the qualitative and quantitative analysis results of elementsmeasured according to “General Rules for X-ray Fluorescence Analysis”described in JIS K 0119:2008.

The atomic ratios of copper, iron, and aluminum are computed from therespective content ratios of copper (II) oxide (CuO), iron (II) oxide(Fe₂O₃), and aluminum oxide (Al₂O₃) determined according to the presentmethod. The sum of the content ratios of calcium oxide (CaO) and silicondioxide (SiO₂) determined according to the present method is used as thecontent ratio of calcium silicate.

(Fourth Step)

The fourth step is a step for calcining the dried product of thecoprecipitated mixture obtained in the third step at a temperature in arange of 500° C. to 1,000° C.

When the dried product is calcined and, if necessary, crushed, thecopper-based catalyst precursor is obtained. At this stage, thecopper-based catalyst precursor has a powder form, and hereinafter,there are cases in which the copper-based catalyst precursor will bereferred to as the powder-form copper-based catalyst precursor.

The formed copper-based catalyst precursor (hereinafter, referred to asthe formed copper-based catalyst precursor), which is easily used in afixed-bed reaction, can be obtained by forming and then calcining thedried product of the coprecipitated mixture or by casting thepowder-form copper-based catalyst precursor.

The calcination temperature is in a range of 500° C. to 1,000° C. In acase in which the calcination temperature is lower than 500° C., thespinel structure is not sufficiently formed, and thus the catalystactivity per unit weight of copper is low, and the catalyst activitysignificantly degrades over time. On the other hand, in a case in whichthe calcination temperature exceeds 1,000° C., the pore volume isdecreased due to melting and fixing, the catalyst activity degrades,thus, the copper-based catalyst precursor is fixed to a calcinationkiln, and the yield of the copper-based catalyst precursor is decreased.From the same viewpoint, the calcination temperature is more preferablyin a range of 600° C. to 900° C., and still more preferably in a rangeof 700° C. to 900° C.

The dried product is preferably calcined in an air atmosphere, an oxygenatmosphere, a hydrogen atmosphere, or an inert gas atmosphere such asnitrogen or argon, and from the viewpoint of convenience, the driedproduct is more preferably calcined in an air atmosphere. In a case inwhich the dried product is calcined in a hydrogen atmosphere, there arecases in which catalyst performance is degraded due to the crystalgrowth (so-called sintering) of the copper metal, and thus caution isrequired.

The gas pressure during the calcining can be selected from theatmospheric pressure or higher. From the viewpoint of the convenience ofan apparatus for producing the copper-based catalyst and the improvementin the formation speed of the spinel structure, the dried product ispreferably calcined at the atmospheric pressure. The calcination time isnot particularly limited; however, generally, is preferably in a rangeof 1 hour to 12 hours, more preferably in a range of 2 hours to 10hours, and still more preferably in a range of 4 hours to 8 hours.

As a method for producing the formed copper-based catalyst precursor, amethod in which additives such as a forming aid, a pore supplying agent,a strengthening agent, and a binder such as clay are added to the driedproduct of the coprecipitated mixture or the powder-form copper-basedcatalyst precursor, and the mixture is extruded or compressed can bepreferably applied. The additives are used depending on the necessity ofobtaining the desired viscosity of paste or the porosity of the formedcopper-based catalyst precursor, and the amount of the additives used ispreferably in a range of 0.5% by mass to 20% by mass, and morepreferably in a range of 1% by mass to 10% by mass of the total mixture.

Examples of the forming aid include graphite, carbon black, talc,starch, polyacrylic acid, methyl cellulose, glycerin monostearate,glycerin monooleate, liquid paraffin, mineral oil, plant oil, stearicacid, magnesium stearate, potassium stearate, palmitic acid, magnesiumpalmitate, potassium palmitate, and the like. Examples of the poresupplying agent include graphite, organic polymer powder such aspolypropylene, sugars, starch, cellulose, and the like. In addition,examples of a strengthening material such as inorganic fibers includeglass fibers and the like.

The shape of the formed copper-based catalyst precursor may be any shapecalled a tablet, a 2 spoke ring, an extrusion, a pellet, a ribextrusion, a trilobe, and a ring; however, from the viewpoint of thesuppression of catalyst pulverization during loading into a reactiontube, a tablet or a 2 spoke ring, which is a compressed product having ahigh crushing strength, is preferred. A tablet is more preferred sinceit is possible to increase the amount of the copper-based catalystprecursor loaded into the reaction tube, and the pressure loss at thereaction tube outlet is decreased. There is no particular limitationregarding the size of the tablet; however, when the tablet has acylindrical shape, it is preferable that the diameter is in a range of0.5 mm to 10 mm, and the thickness is in a range of 0.5 mm to 10 mm, andit is more preferable that the diameter is in a range of 1 mm to 4 mm,and the thickness is in a range of 1 mm to 4 mm. When the copper-basedcatalyst precursor becomes not too large, the contact efficiency of thematrix does not decrease, and the amount of the copper-based catalystprecursor loaded into the reaction tube does not decrease, and thus thevolume efficiency tends to increase. On the other hand, when thecopper-based catalyst precursor becomes not too small, there is no casein which the matrix drifts due to an increase in the pressure loss, andthere is a tendency that an excessive temperature increase and sidereactions are suppressed.

[Method for Using the Copper-Based Catalyst Precursor]

Hereinafter, a method for using the copper-based catalyst precursor (thepowder-form copper-based catalyst precursor and the formed copper-basedcatalyst precursor) will be described.

The copper-based catalyst precursor of the present invention can behelpfully used in the isomerization reaction of a compound having aβ,γ-unsaturated alcohol portion, the hydrogenation reaction of acompound having either or both a carbon-carbon double bond and acarbon-oxygen double bond, and the like.

However, copper included in the copper-based catalyst precursor is in amonovalent or divalent oxidation state, and thus, in a case in which thecopper-based catalyst precursor is used in the above-described reactionsand the like, the copper-based catalyst precursor does not sufficientlydevelop the catalyst function. Therefore, it is necessary to reduce thecopper-based catalyst precursor in advance so that copper in thecopper-based catalyst precursor becomes neutral or, when theabove-described reactions are caused, create conditions in the reactionsystem so that copper is reduced.

A method for reducing the copper-based catalyst precursor without anysolvents will be described. This method can be applied in a case inwhich, for example, the powder-form copper-based catalyst is used in aslurry-bed reaction method, a fluidized-bed reaction method, or afixed-bed reaction method and in a case in which the formed copper-basedcatalyst is used in the fixed-bed reaction method.

In a case in which the powder-form or formed copper-based catalystprecursor is reduced without any solvents using reducing gas, there arecases in which the copper-based catalyst precursor generates heat. Inthis case, sintering by heat generation is accelerated, and thus it isalso possible to use the copper-based catalyst precursor after dilutingthe copper-based catalyst precursor with glass beads, silica, alumina,silicon carbide, or the like for the purpose of reducing theconcentration of the copper-based catalyst per unit volume andincreasing the heat removal efficiency.

In the reduction, reducing gas such as hydrogen or carbon monoxide ispreferably used. The reducing gas may be appropriately diluted withinert gas such as nitrogen, helium, or argon. It is usual and preferableto use hydrogen as the reducing gas and nitrogen as the inert gas fordilution.

The reducing temperature is preferably in a range of 100° C. to 800° C.,and more preferably in a range of 150° C. to 250° C. When the reducingtemperature is 100° C. or higher, water molecules generated due to thereduction of the copper-based catalyst precursor are sufficientlyremoved, the necessary reducing time becomes short, and the copper-basedcatalyst precursor is sufficiently reduced. On the other hand, thereducing temperature is 800° C. or lower, there is no concern ofcatalyst performance being degraded due to the sintering of copper.

The pressure of the reducing gas is preferably in a range of 0.01 MPa(G) to 1.9 MPa (G). Since a higher pressure of the reducing gasfacilitates the proceeding of sintering, it is more preferable to reducethe copper-based catalyst precursor at a pressure close to theatmospheric pressure as much as possible.

There is no particular limitation regarding the flow rate of thereducing gas, but the gas hourly space velocity (GHSV), which isobtained by dividing the supply gas volume velocity (m³/hr) by thevolume (m³) of a catalyst layer made of the copper-based catalystprecursor that may include a diluted substance, is preferably in a rangeof 50 hr⁻¹ to 20,000 hr⁻¹, and more preferably in a range of 100 hr⁻¹ to10,000 hr⁻¹. When the gas hourly space velocity is 50 hr⁻¹ or more, theefficiency of removing moisture generated due to the reduction is high,and the necessary reducing time becomes short, and thus there is noconcern of sintering by the heat storage of the copper-based catalyst.In addition, when the gas hourly space velocity is 20,000 hr⁻¹ or less,the amount of energy required to maintain the temperature of thecatalyst layer is small, which is economically preferable.

The necessary reducing time appropriately varies depending on thereducing temperature and the like; however, generally, it is preferableto continue the reduction until at least one of the generation of waterand the absorption of the reducing gas becomes unobservable.

Generally, it is preferable to install the copper-based catalystobtained through the above-described reduction treatment in the samereaction tube and directly introduce the matrix into the copper-basedcatalyst, thereby promoting desired reactions from the viewpoint ofavoiding risks such as the ignition of the copper-based catalyst andimproving the productivity of the target substance.

Next, a method for reducing the copper-based catalyst precursor in asolvent will be described. This method can be applied in a case in whichthe powder-form copper-based catalyst is used in a slurry-bed reactionmethod.

The copper-based catalyst precursor is reduced after being immersed in asolvent that does not poison copper-based catalysts. There is noparticular limitation regarding the solvent, and alcohols, ethers,hydrocarbons, and the like can be preferably used. Examples of thealcohols include methanol, ethanol, octanol, dodecanol, and the like.Examples of the ethers include tetrahydrofuran, dioxane, tetraethyleneglycol dimethyl ether, and the like. Examples of the hydrocarbonsinclude hexane, cyclohexane, decalin, liquid paraffin, and the like.

Examples of a reducing agent used for the reduction of the copper-basedcatalyst precursor include hydrogen, carbon monoxide, ammonia,hydrazine, formaldehyde, lower alcohols such as methanol, and the like.The reducing agent may be singly used, or a mixture of two or morereducing agents may be used. In addition, the reducing agent may bediluted using an inert gas such as nitrogen, helium, or argon beforebeing used. It is usual and preferable to use hydrogen as the reducingagent and nitrogen as the inert gas for dilution.

The reducing temperature is preferably in a range of 100° C. to 800° C.,and more preferably in a range of 100° C. to 300° C. When the reducingtemperature is 100° C. or higher, water molecules generated due to thereduction of the copper-based catalyst precursor are sufficientlyremoved, the necessary reducing time becomes short, and the copper-basedcatalyst precursor is sufficiently reduced. On the other hand, thereducing temperature is 800° C. or lower, there is no concern ofcatalyst performance being degraded due to the sintering of copper.

In a case in which a reducing gas such as hydrogen, carbon monoxide, orammonia is used, the pressure of the reducing gas is preferably in arange of 0.01 MPa (G) to 10 MPa (G). Since a higher pressure of thereducing gas facilitates the proceeding of sintering, it is morepreferable to reduce the copper-based catalyst precursor at a pressureclose to the atmospheric pressure as much as possible. Furthermore, itis more preferable to shorten the reduction time by bubbling thereducing gas in the suspension and efficiently removing water moleculesgenerated due to the reduction.

The necessary reducing time is appropriately varied depending on thereducing temperature and the like; however, generally, it is preferableto continue the reduction until at least one of the generation of waterand the absorption of the reducing gas becomes unobservable.

While it is also possible to separate the copper-based catalyst obtainedthrough the above-described reduction treatment through filtration orthe like and then introduce the copper-based catalyst into a desiredreaction system, generally, it is preferable to introduce a reactionmatrix into the suspension of the copper-based catalyst, therebypromoting desired reactions from the viewpoint of avoiding risks such asthe ignition of the copper-based catalyst and improving the productivityof the target substance.

(Isomerization Reaction of a Compound Having a β,γ-Unsaturated AlcoholPortion)

An aldehyde compound can be produced using an isomerization reaction ofa compound having a β,γ-unsaturated alcohol portion in which thecopper-based catalyst precursor of the present invention is used. Asdescribed above, the copper-based catalyst precursor is used after beingreduced.

The isomerization reaction can be caused in a liquid phase or a gasphase using a reaction method such as a slurry-bed reaction method, afluidized-bed reaction method, or a fixed-bed reaction method. However,in a case in which the reaction system is exposed to a high temperaturefor a long period of time, aldehydes being generated are thermallyunstable, and thus the fixed-bed reaction method is preferably used fromthe viewpoint of a concern of the generation of high-boiling pointsubstances, the conversion ratio, and the selectivity. In addition, theisomerization reaction is preferably caused in a gas phase.

Hereinafter, an isomerization reaction method in which the fixed-bedreaction method is used will be specifically described, but the methodfor using the copper-based catalyst (precursor) is not limited thereto.

The scope of the “compound having a β,γ-unsaturated alcohol portion”which is a matrix of the present isomerization reaction includescompounds which have a —C═C—C—OH portion and have a total of 4 to 30carbon atoms. Examples thereof include 2-butene-1-ol, 2-pentene-1-ol,2-hexene-1-ol, 2-heptene-1-ol, 2-octene-1-ol, 2,7-octadiene-1-ol,2-nonene-1-ol, 2-decene-1-ol, 3-phenyl-2-propene-1-ol,4-phenyl-2-butene-1-ol, 5-phenyl-2-pentene-1-ol, 6-phenyl-2-hexene-1-ol,7-phenyl-2-heptene-1-ol, 8-phenyl-2-octene-1-ol, 9-phenyl-2-nonene-1-ol,10-phenyl-2-decene-1-ol, 2-methyl-2-butene-1-ol,2-methyl-2-pentene-1-ol, 2-methyl-2-hexene-1-ol,2-methyl-2-heptene-1-ol, 2-methyl-2-octene-1-ol, 2-methyl-2-nonene-1-ol,2-methyl-2-decene-1-ol, 6-benzyl-2-cyclohexene-1-ol,4-phenyl-1-vinyl-cyclohexane-1-ol, and the like. Among them, thecopper-based catalyst precursor of the present invention is useful forthe isomerization reaction of 2,7-octadiene-1-ol.

If desired, it is also possible to use a matrix diluted in a solventthat does not poison copper-based catalysts. There is no particularlimitation regarding the solvent, and examples thereof include alcohols,ethers, and hydrocarbons. Examples of the alcohols include methanol,ethanol, octanol, dodecanol, 7-octene-1-ol, and the like. Examples ofthe ethers include tetrahydrofuran, dioxane, tetraethylene glycoldimethyl ether, and the like. Examples of the hydrocarbons includehexane, cyclohexane, decalin, liquid paraffin, and the like. In somecases, it is also possible to use water as the solvent.

In a case in which 7-octene-1-ol is used as the solvent among theabove-described solvents, some of the 7-octene-1-ol is converted to7-octenal in the isomerization reaction system, and thus the use of7-octene-1-ol is preferred from the viewpoint of the improvement ofproductivity in a case in which 7-octenal is produced.

When a fixed-bed reactor loaded with the copper-based catalyst obtainedthrough reduction is placed at a desired temperature and a desiredpressure, and a compound having a β,γ-unsaturated alcohol portion and agas mixture made up of an inert gas and a reducing gas or an inert gasare supplied to the fixed-bed reactor at the same time, theisomerization reaction of the compound having a β,γ-unsaturated alcoholportion proceeds, and an aldehyde compound can be produced.

From the viewpoint of producing the uniform gas flow, the fixed-bedreactor is preferably a reactor having a tubular structure, and when thetemperature of the copper-based catalyst being uniformly controlled istaken into account, a reactor having a multitubular structure in whichmultiple reaction tubes are disposed in parallel is more preferred. Areaction tube having a round cross-sectional shape is generally used asthe reaction tube. From the viewpoint of ease of a catalyst loadingoperation and the uniform loading of the copper-based catalyst, it ispreferable to vertically dispose linear straight tubes.

The tube diameter is not particularly limited, but is preferably in arange of 15 mm to 50 mm, and more preferably in a range of 20 mm to 40mm. When the tube diameter is 15 mm or more, it is possible to suppressan increase in the number of reaction tubes, and thus the productioncost of the reactor can be reduced. In addition, when the tube diameteris 50 mm or less, it is possible to suppress the heat storage of thecopper-based catalyst in the tube center portion, and thus theacceleration of catalyst deactivation, a sequential reaction, a runawayreaction, and the like can be suppressed.

There is no particular limitation regarding the length and number of thereaction tubes, and it is preferable to appropriately set the length andnumber of the reaction tubes in consideration of the production cost ofthe reactor, the amount of the copper-based catalyst required to achievea desired producing capability, and the like. Generally, a method inwhich the fixed-bed multitubular reactor is used as a heat exchangereactor, jackets are provided at the outside of the reaction tubesloaded with the copper-based catalyst, and steam, heated oil, or thelike is made to pass through the jackets, thereby controlling thereaction temperature is preferably employed. The state of the matrix inthe reaction system may be any of a liquid state or a gas state;however, from the viewpoint of maintaining the matrix conversion ratioat a high level in order to allow the matrix molecules to diffuse intothe inside of the copper-based catalyst and suppressing the degradationof the catalyst activity due to the carbonization and the like of thematrix and a product on the surface of the copper-based catalyst, thematrix is preferably in a gas state.

The reaction temperature is preferably in a range of 100° C. to 800° C.When the reaction temperature is 100° C. or higher, the reactionactivation energy is sufficient, and thus sufficient productivity can beachieved. When the reaction temperature is 800° C. or lower, a decreasein the yield of the target substance due to the thermal decomposition ofthe matrix or the product is suppressed, and furthermore, there is noconcern that productivity may be decreased by the carbide of the matrixor the product covering the surface of the copper-based catalyst orcatalyst performance may be decreased by the sintering of copper. Fromthe same viewpoint, the reaction temperature is preferably in a range of100° C. to 500° C., more preferably in a range of 100° C. to 300° C.,and still more preferably in a range of 150° C. to 250° C.

The reaction pressure is preferably in a range of 0.01 MPa (G) to 1.9MPa (G) from the viewpoint of the easy control of pressure and thereduction of reaction facility cost. From the viewpoint of improving theproductivity by increasing the diffusion efficiency of the matrix intothe copper-based catalyst, it is more preferable to use the matrix in agas phase, and it is more preferable to set the pressure close to 0.01MPa (G) as much as possible.

Together with the matrix, an inert gas or a gas mixture made up of areducing gas and an inert gas is supplied. In the gas mixture, thecontent of the reducing gas is preferably in a range of 0.05% by volumeto 20% by volume, more preferably in a range of 0.1% by volume to 15% byvolume, and still more preferably in a range of 0.1% by volume to 10% byvolume.

The fixed-bed reactor may be any of a down-flow reactor in which thecomponents are supplied from the upper portion of the reactor or anup-flow reactor in which the components are supplied from the lowerportion of the reactor; however, from the viewpoint of steadily removingliquid-phase high-boiling point substances, which are reactionbyproducts, outside the system, the down-flow reactor is preferred.

From the viewpoint of cheap prices, hydrogen gas is preferably used asthe reducing gas, and nitrogen gas is preferably used as the inert gas.There is no particular limitation regarding the amount of hydrogen gassupplied, but the number of hydrogen molecules is desirably equal to ormore than the number of oxygen molecules included in nitrogen gas andthe matrix. Conversely, in a case in which the number of hydrogenmolecules supplied is excessively large, the hydrogenation of the matrixproceeds, and thus the selectivity of the target substance is degraded.Furthermore, it is necessary to appropriately select the contactefficiency between the copper-based catalyst and reducing gas moleculesdepending on physical properties such as the shape of the copper-basedcatalyst being used and the molecule diffusion rate, and thus it isnecessary adjust the amount of the matrix supplied, the amount of thegas mixture supplied, the content of the reducing gas included in thegas mixture, and the like so that desired reactions and desired reactionachievement are achieved.

Regarding the amount of hydrogen gas supplied together with the matrix,the molecular ratio (molar ratio) of the matrix to the hydrogen gas[matrix/hydrogen gas] is preferably in a range of 99/1 to 75/25, morepreferably in a range of 99/1 to 80/20, and still more preferably in arange of 97/3 to 80/20. When the molecular ratio (molar ratio)[matrix/hydrogen gas] is too small, that is, the amount of the hydrogengas is too great, there is a concern that the selectivity of thealdehyde compound may be decreased. From the viewpoint of suppressingthe generation of a dehydrogenated compound being accelerated, it ispreferable to prevent the molecular ratio (molar ratio) [matrix/hydrogengas] from becoming too great, that is, prevent the amount of thehydrogen gas from becoming too small.

There is no particular limitation regarding the amount of the matrixsupplied, but the weight hourly space velocity (WHSV), which is obtainedby dividing the weight of the matrix supplied (kg/hr) by the weight ofthe copper-based catalyst precursor (kg), is preferably in a range of0.05 hr⁻¹ to 20 hr⁻¹, and more preferably in a range of 0.1 hr⁻¹ to 10hr⁻¹. When the weight hourly space velocity is 0.05 hr⁻¹ or more, thecontact time between the matrix, the product, and the copper-basedcatalyst becomes short, and it is possible to suppress the generation ofthe condensate of the matrix or the product or a decrease in the yieldof the target substance due to the carbonization of the matrix or theproduct. When the weight hourly space velocity is 20 hr⁻¹ or less, theamount of energy required to maintain the temperature of the catalystlayer is small, which is economically preferable.

There is no particular limitation regarding the flow rate of the inertgas or the gas mixture, but the gas hourly space velocity (GHSV), whichis obtained by dividing the supply gas volume velocity (m³/hr) by thevolume (m³) of the catalyst layer made of the copper-based catalystprecursor that may include a diluted substance, is preferably in a rangeof 50 hr⁻¹ to 20,000 hr⁻¹, and more preferably in a range of 100 hr⁻¹ to10,000 hr⁻¹. When the gas hourly space velocity is 50 hr⁻¹ or more,there is no concern of sintering due to the heat storage of thecopper-based catalyst. In addition, when the gas hourly space velocityis 10,000 hr⁻¹ or less, the amount of energy required to maintain thetemperature of the catalyst layer is small, which is economicallypreferable.

When the product discharged together with gas is liquefied using anagglomerating device, and is distilled at the atmospheric pressure orreduced pressure, it is possible to separate and purify the aldehydecompound which is the target substance.

When the reaction is continuously caused, there are cases in which thedegradation of the catalyst activity is observed. In this case, thecopper-based catalyst may be used after the copper-based catalyst usedin the reaction is appropriately fired in the air or an oxygenatmosphere under pressurization in a range of 0.01 MPa (G) to 1.9 MPa(G) at a temperature in a range of the reaction temperature to 800° C.so as to carbonize organic compounds attached to the surface of thecopper-based catalyst, the carbonized organic compounds are removed, andthen the reduction treatment is carried out again.

(Hydrogenation Reaction of the Compound Having a Carbon-Carbon DoubleBond or a Carbon-Oxygen Double Bond)

When the copper-based catalyst precursor of the present invention isused, it is possible to efficiently cause the hydrogenation reaction ofthe compound having either or both a carbon-carbon double bond and acarbon-oxygen double bond.

The hydrogenation reaction of a compound having a carbon-carbon doublebond and a carbon-oxygen double bond can be caused using any reactionmethod of a slurry-bed reaction method, a fluidized-bed reaction method,and a fixed-bed reaction method. In a case in which the hydrogenationreaction is caused using the fixed-bed reaction method, the reaction canbe caused under the same conditions as the isomerization reactionconditions for the compound having a β,γ-unsaturated alcohol portionexcept for the fact that the content of the hydrogen gas included in thegas mixture is preferably selected from a range of 1% by volume to 100%by volume, more preferably selected from a range of 50% by volume to100% by volume, and still more preferably selected from a range of 80%by volume to 100% by volume.

Hereinafter, a hydrogenation reaction in which the slurry-bed reactionmethod is used will be specifically described, but the method for usingthe copper-based catalyst is not limited thereto.

The scope of the “compound having a carbon-carbon double bond” which isa matrix of the present hydrogenation reaction includes all compoundshaving a —C═C— portion. In the concept of the carbon-carbon double bond,double bonds formed by adding a carbon-carbon triple bond are alsoincluded.

In addition, the scope of the “compound having a carbon-oxygen doublebond” which is another matrix of the present hydrogenation reactionincludes all compounds having a —(C═O)— portion, and examples thereofinclude aldehydes, ketones, carboxylic acids, esters, acid anhydrides,sugars, and the like. In addition, compounds having a plurality of theabove-described portion in a molecule are also included.

The matrix of the present hydrogenation reaction is preferably selectedfrom the group consisting of aldehydes which may include a carbon-carbondouble bond, ketones which may include a carbon-carbon double bond,carboxylic acids which may include a carbon-carbon double bond, esterswhich may include a carbon-carbon double bond, acid anhydrides which mayinclude a carbon-carbon double bond, and sugars which may include acarbon-carbon double bond. In addition, from the viewpoint of the easyseparation of the product, the matrix of the present hydrogenationreaction is preferably a compound having a total of 4 to 30 carbon atomsin a molecule, more preferably a compound having a total of 4 to 20carbon atoms in a molecule, and still more preferably a compound havinga total of 4 to 10 carbon atoms in a molecule.

Examples of the compounds having a carbon-carbon double bond includeunsaturated aliphatic hydrocarbons, unsaturated aliphaticgroup-containing aromatic hydrocarbons, alicyclic olefin-basedhydrocarbons, olefins having a functional group, and the like.

Examples of the unsaturated aliphatic hydrocarbons include ethylene,propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene,2-butene, isobutene, 2-octene, 1,7-octadiene, vinyl cyclohexene,cyclooctadiene, dicyclopentadiene, butadiene polymers, isoprenepolymers, and the like. Examples of the unsaturated aliphaticgroup-containing aromatic hydrocarbons include styrene, α-methylstyrene,β-methylstyrene, alkyl group nucleus-substituted styrene, divinylbenzene, and the like. Examples of the alicyclic olefin-basedhydrocarbons include cyclopentene, cyclohexene, 1-methylcyclohexene,cyclooctene, limonene, and the like. Examples of the olefins having afunctional group include allyl alcohol, crotyl alcohol,3-methyl-3-butene-1-ol, 7-octene-1-ol, 2,7-octadienol, vinyl acetate,allyl acetate, methyl acrylate, ethyl acrylate, methyl methacrylate,allyl acrylate, vinyl methyl ether, allyl ethyl ether, 5-hexeneamide,acrylonitrile, 7-octenal, and the like.

In addition, there are also natural compounds having a carbon-carbondouble bond, and examples of the natural compounds include vegetable oilsuch as soybean oil, canola oil, sunflower seed oil, cotton oil,earthnut oil, sesame oil, palm oil, palm kernel oil, flaxseed oil,castor oil, or coconut oil; animal oil such as beef fat, fish oil, orlard; unsaturated aliphatic acids obtained therefrom, and the like.

Among them, the copper-based catalyst precursor of the present inventionis useful for the hydrogenation reaction of 7-octenal.

Specific examples of aldehydes, ketones, carboxylic acids, esters, acidanhydrides, and sugars as the compounds having a carbon-oxygen doublebond will be described below.

Examples of the aldehyde compounds include formaldehyde,propionaldehyde, n-butylaldehyde, isobutylaldehyde, valeraldehyde,2-methyl butylaldehyde, 3-methyl butylaldehyde, 2,2-dimethylpropionaldehyde, capronaldehyde, 2-methyl valeraldehyde, 3-methylvaleraldehyde, 4-methyl valeraldehyde, 2-ethyl butylaldehyde,2,2-dimethyl butylaldehyde, 3,3-dimethyl butylaldehyde, caprilaldehyde,capric aldehyde, glutardialdehyde, 7-octenal, and the like.

Furthermore, the aldehyde compounds may be hydroxyaldehyde compoundshaving a hydroxyl group in the molecule, and examples thereof include3-hydroxypropanal, dimethylol ethanal, trimethylol ethanal,3-hydroxybutanal, 3-hydroxy-2-ethylhexanal, 3-hydroxy-2-methylpentanal,2-methylolpropanal, 2,2-dimethylolpropanal, 3-hydroxy-2-methylbutanal,3-hydroxypentanal, 2-methylolbutanal, 2,2-dimethylolbutanal,hydroxypivalic aldehyde, and the like.

Examples of the ketone compounds include acetone, butanone, 2-pentanone,4-methyl-2-pentanone, 2-hexanone, cyclohexanone, isoboron, methylisobutyl ketone, mesityl oxide, acetophenone, propiophenone,benzophenone, benzalactone, dibenzalactone, benzalactophenone,2,3-butadion, 2,4-pentadion, 2,5-hexadion, 5-methyl vinyl ketone, andthe like.

Among them, the copper-based catalyst precursor of the present inventionis useful for the hydrogenation reaction of 4-methyl-2-pentanone.

Examples of the carboxylic acids include formic acid, acetic acid,propionic acid, butyric acid, isobutyric acid, n-valeric acid,trimethylacetic acid, caproic acid, enanthylic acid, capric acid, lauricacid, myristic acid, palmitic acid, stearic acid, acrylic acid,methacrylic acid, oleic acid, elaidic acid, linoleic acid, linolenicacid, cyclohexane carboxylic acid, benzoic acid, phenylacetic acid,ortho-toluic acid, meta-toluic acid, para-toluic acid,ortho-chlorobenzoic acid, para-chlorobenzoic acid, ortho-nitrobenzoicacid, para-nitrobenzoic acid, salicylic acid, para-hydroxybenzoic acid,anthranilic acid, para-aminobenzoic acid, oxalic acid, maleic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, maleic acid, fumaric acid, isofumaric acid, terephthalicacid, 1,2-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylicacid, and the like.

Furthermore, the carboxylic acids may be esterified compounds made up ofa carboxylic acid and an alcohol, and the alcohol component constitutingthe ester is not particularly limited; however, the alcohol component isgenerally an aliphatic or alicyclic alcohol having 1 to 6 carbon atoms,and examples thereof include methanol, ethanol, propanol, butanol,pentanol, hexanol, cyclohexanol, and the like. Furthermore, lactones asesters cyclized in the molecule, for example, γ-butyrolactone,δ-valerolactone, and ε-caprolactone are also included.

If desired, it is also possible to use a matrix diluted in a solventthat does not poison copper-based catalysts. There is no particularlimitation regarding the solvent, and examples thereof include alcohols,ethers, and hydrocarbons. Examples of the alcohols include methanol,ethanol, octanol, dodecanol, and the like. Examples of the ethersinclude tetrahydrofuran, dioxane, tetraethylene glycol dimethyl ether,and the like. Examples of the hydrocarbons include hexane, cyclohexane,decalin, liquid paraffin, and the like. In some cases, it is alsopossible to use at least one selected from water, matrixes, and productsas the solvent.

The slurry-bed reaction method can be selected from two methods of abatch method (including a half continuous method) and a flow continuousmethod, and the flow continuous method in which the copper-basedcatalyst is easily collected and used is preferred. Hereinafter, theslurry-bed reaction method in which the flow continuous method is usedwill be briefly described.

When a slurry-bed reactor loaded with a suspension obtained through thereduction treatment of the copper-based catalyst precursor is placed ata desired temperature and a desired pressure, and a compound havingeither or both a carbon-carbon double bond and a carbon-oxygen doublebond and hydrogen gas are supplied, hydrogenation can be caused.

Since a decrease in the size of the powder-form copper-based catalystprecursor increases the specific area per unit weight, the catalystactivity per unit mass of the copper-based catalyst becomes high. On theother hand, an increase in the size facilitates filtration after thereaction. From such a viewpoint, generally, a powder-form copper-basedcatalyst precursor screened with a mesh in a range of 16 to 400 ispreferably used. The concentration of the powder-form copper-basedcatalyst included in the suspension is preferably in a range of 0.01% bymass to 50% by mass, and, from the viewpoint of the productivity perunit time and the properties of the powder-form copper-based catalystbeing removed by filtration, is more preferably in a range of 1% by massto 10% by mass.

The hydrogenation reaction temperature is preferably in a range of 100°C. to 800° C., more preferably in a range of 100° C. to 300° C., andstill more preferably in a range of 150° C. to 250° C. When the reactiontemperature is 100° C. or higher, the reaction activation energy becomessufficient, and sufficient productivity can be achieved. In addition,when the reaction temperature is 800° C. or lower, a decrease in theyield of the target substance due to the thermal decomposition of thematrix and the product is suppressed, and furthermore, the degradationof productivity due to the surfaces of the copper-based catalyst coveredwith the carbide of the matrix or the product or the degradation ofcatalyst performance due to the sintering of copper is suppressed.

Generally, the hydrogen pressure is preferably selected from a range of1 MPa (G) to 30 MPa (G). In the hydrogenation reaction in which theslurry-bed method is used, an increase in the hydrogen pressureincreases the number of hydrogen molecules being dissolved in thesolvent, and accordingly, the reaction rate improves, and therefore thepressure is preferably high even in the above-described hydrogenpressure range.

For the separation of the liquid-phase product and the copper-basedcatalyst, a method such as decantation or filtration can be employed.The separated copper-based catalyst that has been used before can bereused by washing the copper-based catalyst using an alcohol, an ether,a hydrocarbon solvent, or the like, then, bringing the copper-basedcatalyst into contact with the air, and carrying out calcination and thereducing treatment on the copper-based catalyst. The target substancecan be separated and purified by distilling a liquid from which thecopper-based catalyst has been separated in the atmosphere or at areduced pressure.

EXAMPLES

Hereinafter, the present invention will be described in more detailusing examples, but the present invention is not limited to the examplesby any means.

The method for producing the copper-based catalyst precursor in thepresent invention will be described in detail in Examples 1 to 7. Inaddition, a method for producing a catalyst precursor for comparingcatalyst performance will be described in detail in Reference Examples 1to 5.

The atomic ratios of Cu, Fe, and Al and the content (% by mass) ofcalcium silicate are values based on the qualitative and quantitativeanalysis results of the elements measured from the dried product of thecoprecipitated mixture obtained in the third step according to “GeneralRules for X-ray Fluorescence Analysis” described in JIS K 0119:2008using a tube-above wavelength dispersive X-ray fluorescence spectrometer“ZSX Primus II” manufactured by Rigaku Corporation. The Cu/Fe/Al atomicratios were computed from the content (% by mass) of copper (II) oxide(CuO), the content (% by mass) of iron (II) oxide (Fe₂O₃), and thecontent (% by mass) of aluminum oxide (Al₂O₃) determined according tothe present method, and furthermore, (Fe+Al)/Cu and Al/Fe were obtained.The sum of the content (% by mass) of calcium oxide (CaO) and thecontent (% by mass) of silicon oxide (SiO₂) determined according to thepresent method was used as the content (% by mass) of calcium silicate.

In addition, the BET specific surface area is a value based on thenitrogen adsorption specific surface area measured from the driedproduct of the coprecipitated mixture obtained in the third stepaccording to “Determination Of The Specific Surface Area Of Powders(Solids) By Gas Adsorption Methods” described in JIS Z8830:2001 using“GEMINI VII2390” manufactured by Micromeritics Japan.

In the respective examples described below, unless particularlyotherwise described, ion exchange water was used as water, and operationwere carried out in an air atmosphere having the atmospheric pressure.

Example 1

17.5 g (0.178 mol) of sulfuric acid, 94.2 g of copper (II) sulfatepentahydrate (0.377 mol of copper atom), 170.8 g of iron (I) sulfateheptahydrate (0.614 mol of iron atom), and 132.6 g of liquid aluminumsulfate (containing 8% of Al₂O₃) (0.208 mol of aluminum atom) weresequentially added to 2,000 g of water in a 5 L glass beaker including astirrer and a heating device, were sufficiently stirred so as to preparea uniform aqueous solution of metal sulfate, and the aqueous solutionwas heated to 50° C., and was maintained.

120 g of sodium hydroxide was dissolved in 2,000 g of water in a 10 Lglass beaker including a stirrer and a heating device, and the solutionwas heated to 80° C. In a state in which the mixture was being stirredso as to prevent a coprecipitate from settling and accumulating evenafter the completion of the dropwise addition of the aqueous solution ofmetal sulfate, the aqueous solution of metal sulfate was added dropwiseto an aqueous solution of sodium hydroxide using a metering pump over120 minutes. At this time, the heating device was controlled so that thetemperature of the reaction solution was maintained at 80° C.

After the completion of the dropwise addition, the aqueous solutionmixture was aged for 1 hour at the same temperature in the same stirringstate. After that, the aqueous solution mixture was cooled to 50° C.,and was left to stand. Supernatant was removed through decantation,4,000 g of first washing water was added, and the coprecipitate wasstirred at 50° C., thereby washing the coprecipitate. This operation wasrepeated, and it was confirmed that the pH of the supernatant was 7.7after the injection of fifth washing water. In a state in which thefifth washing water was present and the coprecipitate was being stirredat 50° C. so as to prevent the settlement of the coprecipitate, 75.0 gof calcium silicate (manufactured by Tomita Pharmaceutical Co., Ltd.,“FLORITE”) was added, and the mixture was aged for 1 hour. Thecoprecipitated mixture was filtered at room temperature, and was driedin the air at 120° C. for 16 hours. The dried product of the obtainedcoprecipitated mixture was calcined at 800° C. in the air having theatmospheric pressure for 6 hours, thereby obtaining a powder-formcopper-based catalyst precursor. The powder-form copper-based catalystprecursor obtained in the above-described manner will be referred to asa catalyst precursor A.

Example 2

The same operation was carried out in Example 1 except for the fact thatsulfuric acid (17.5 g, 0.178 mol), copper (II) sulfate pentahydrate(94.2 g, 0.377 mol of copper atom), iron (I) sulfate heptahydrate (113.9g, 0.410 mol of iron atom), and liquid aluminum sulfate (215.8 g, 0.339mol of aluminum atom) were sequentially added so as to prepare a uniformaqueous solution of metal sulfate, and 86.7 g of calcium silicate(manufactured by Tomita Pharmaceutical Co., Ltd., “FLORITE”) was added.The powder-form copper-based catalyst precursor obtained in theabove-described manner will be referred to as a catalyst precursor B.

Example 3

The same operation was carried out in Example 1 except for the fact thatsulfuric acid (17.5 g, 0.178 mol), copper (II) sulfate pentahydrate(94.2 g, 0.377 mol of copper atom), iron (I) sulfate heptahydrate (227.7g, 0.819 mol of iron atom), and liquid aluminum sulfate (7.1 g, 0.011mol of aluminum atom) were sequentially added so as to prepare a uniformaqueous solution of metal sulfate, and 70.2 g of calcium silicate(manufactured by Tomita Pharmaceutical Co., Ltd., “FLORITE”) was added.The powder-form copper-based catalyst precursor obtained in theabove-described manner will be referred to as a catalyst precursor C.

Example 4

The same operation was carried out in Example 1 except for the fact thatsulfuric acid (17.5 g, 0.178 mol), copper (II) sulfate pentahydrate(94.2 g, 0.377 mol of copper atom), iron (I) sulfate heptahydrate (57.0g, 0.205 mol of iron atom), and liquid aluminum sulfate (396.5 g, 0.622mol of aluminum atom) were sequentially added so as to prepare a uniformaqueous solution of metal sulfate, and 89.4 g of calcium silicate(manufactured by Tomita Pharmaceutical Co., Ltd., “FLORITE”) was added.The powder-form copper-based catalyst precursor obtained in theabove-described manner will be referred to as a catalyst precursor D.

Example 5

The same operation was carried out in Example 2 except for the fact thatthe calcination temperature was changed to 600° C., and a powder-formcopper-based catalyst precursor was obtained. The powder-formcopper-based catalyst precursor obtained in the above-described mannerwill be referred to as a catalyst precursor E.

Example 6

The same operation was carried out in Example 1 except for the fact that42.7 g of calcium silicate (manufactured by Tomita Pharmaceutical Co.,Ltd., “FLORITE”) was added. The powder-form copper-based catalystprecursor obtained in the above-described manner will be referred to asa catalyst precursor F.

Example 7

The same operation was carried out in Example 1 except for the fact that24.9 g of calcium silicate (manufactured by Tomita Pharmaceutical Co.,Ltd., “FLORITE”) was added. The powder-form copper-based catalystprecursor obtained in the above-described manner will be referred to asa catalyst precursor G.

Hereinafter, a method for preparing the powder-form copper-basedcatalyst precursor for comparing the catalyst performance of thecopper-based catalyst precursor of the present invention will bedescribed as reference examples.

Copper-based catalyst precursors described in Reference Examples 1 to 3can be prepared in the same manner as a catalyst precursor B; however,γ-alumina was added to the copper-based catalyst precursors instead ofcalcium silicate, and the copper-based catalyst precursors are intendedto exhibit the availability of calcium silicate as a carrier. Thecopper-based catalyst precursor described in Reference Example 4 couldbe prepared in the same manner as the catalyst precursor B, but thecalcination temperature was set to 400° C., and the copper-basedcatalyst precursor was used to clarify the influence of the calcinationtemperature. The copper-based catalyst precursor described in ReferenceExample 5 rarely included iron, and was used to clarify the necessity ofiron.

Reference Example 1

The same operation was carried out in Example 2 except for the fact that86.7 g of γ-alumina (manufactured by C. I. Kasei Co., Ltd., “NanoTekAl₂O₃”) was added instead of 86.7 g of calcium silicate (manufactured byTomita Pharmaceutical Co., Ltd., “FLORITE”). The powder-formcopper-based catalyst precursor obtained in the above-described mannerwill be referred to as a catalyst precursor H1.

Reference Example 2

The same operation was carried out in Reference Example 1 except for thefact that the calcination temperature was changed to 600° C., and apowder-form copper-based catalyst precursor was obtained. Thepowder-form copper-based catalyst precursor obtained in theabove-described manner will be referred to as a catalyst precursor H2.

Reference Example 3

The same operation was carried out in Reference Example 1 except for thefact that the calcination temperature was changed to 400° C., and apowder-form copper-based catalyst precursor was obtained. Thepowder-form copper-based catalyst precursor obtained in theabove-described manner will be referred to as a catalyst precursor H3.

Reference Example 4

The same operation was carried out in Example 2 except for the fact thatthe calcination temperature was changed to 600° C., and a powder-formcopper-based catalyst precursor was obtained. The powder-formcopper-based catalyst precursor obtained in the above-described mannerwill be referred to as a catalyst precursor I.

Reference Example 5

The same operation was carried out in Example 1 except for the fact thatsulfuric acid (17.5 g, 0.178 mol), copper (II) sulfate pentahydrate(94.2 g, 0.377 mol of copper atom), and liquid aluminum sulfate (471.3g, 0.740 mol of aluminum atom) were sequentially added so as to preparea uniform aqueous solution of metal sulfate, and 95.8 g of calciumsilicate (manufactured by Tomita Pharmaceutical Co., Ltd., “FLORITE”)was added. The powder-form copper-based catalyst precursor obtained inthe above-described manner will be referred to as a catalyst precursorJ.

Table 1 describes the analysis values of the dried products of thecoprecipitated mixtures prepared in Examples 1 to 7 and ReferenceExamples 1 to 5.

For the copper-based catalyst precursors except for the copper-basedcatalyst precursors of Reference Examples 1 to 3, the Cu/Fe/Al atomicratios are values computed from the component analysis values of thedried products of the coprecipitated mixtures, and the amount of calciumsilicate is the sum of the % by mass of calcium oxide and silicon oxidein the analysis values of the dried products of the coprecipitatedmixture. Meanwhile, for the copper-based catalyst precursors describedin Reference Examples 1 to 3, the Cu/Fe/Al atomic ratios of thecoprecipitates are values separately computed from the componentanalysis values of the Cu/Fe/Al atomic ratios of the dried products ofthe coprecipitates, and the % by mass of γ-alumina which was used as theadditive during filtration was computed from the difference in componentanalysis value between the dried products and the coprecipitates. Thatis, since γ-alumina was added to the coprecipitates, the dried productsof the present coprecipitated mixtures, substantially, had a Cu/Fe/Alatomic ratio of 1/1.10/0.93, and included 47.6% by mass of γ-alumina.

TABLE 1 Copper- Analysis results Calcination based Calcium BET specifictemper- catalyst (Fe + Al)/ silicate surface area ature precursor CuOFe₂O₃ Al₂O₃ CaO SiO₂ Cu/Fe/Al Cu Al/Fe (% by mass) (m²/g) (° C.) Example1 A 18.0 29.0 6.8 13.4 31.7 1/1.61/0.59 2.2  0.37 45.1 130.5 800 Example2 B 18.2 18.7 10.9 13.7 37.6 1/1.02/0.93 1.95 0.91 51.3 151.8 800Example 3 C 18.3 40.5 0.2 11.8 27.9 1/2.20/0.02 2.22 0.01 39.7 168.4 800Example 4 D 19.1 10.4 18.0 13.9 37.5 1/0.54/1.47 2.01 2.72 51.4 171.4800 Example 5 E 18.2 18.7 10.9 13.7 37.6 1/1.02/0.93 1.95 0.91 51.3151.8 600 Example 6 F 21.8 35.5 7.4  8.0 26.0 1/1.62/0.53 2.15 0.33 34.0134.8 800 Example 7 G 24.6 40.5 8.7  5.3 19.4 1/1.64/0.55 2.19 0.34 24.7131.4 800 Reference H1 18.0 19.8 58.3 0.1 or 0.1 or (1/1.10/5.05), 2.030.85 Instead, 100.2 800 Example 1 less less substantially, 47.6 of γ-Reference H2 1/1.10/0.93 alumina 600 Example 2 added Reference H3 400Example 3 Reference I 18.2 18.7 10.9 13.7 37.6 1/1.02/0.93 1.95 0.9151.3 151.8 400 Example 4 Reference J 20.2 — 22.6 14.9 40.1 1.0/—/1.75 —— 55.0 193.5 800 Example 5

Capabilities of copper-based catalysts obtained by reducing thecopper-based catalyst precursor of the present invention for producingaldehyde compounds using the isomerization of a compound having aβ,γ-unsaturated alcohol portion, more specifically, capabilities forproducing 7-octenal from 2,7-octadiene-1-ol in the fixed-bed reactionmethod in which the copper-based catalyst precursors prepared inExamples 1 to 7 will be described in more detail in Assessment Examples1 to 7.

In addition, in Comparative Assessment Examples 1 to 5, capabilities forproducing 7-octenal in the fixed-bed reaction method in which thecopper-based catalyst obtained by reducing the copper-based catalystprecursor outside the scope of the present invention is used will bedescribed.

Assessment Example 1

50 mL of a mixture obtained by diluting a copper-based catalystprecursor A to 50% by mass using soda glass beads having a diameter in arange of 3.962 mm to 4.699 mm was loaded into an atmospheric pressurecirculation-type stainless steel SUS316 vertical straight reaction tube(inner diameter: 22 mm, length: 1 m) including an electric heater forcontrolling the temperature of a catalyst layer outside, a thermocouplefor measuring the temperature of the catalyst layer inside, a gas supplyopening in the upper portion, and a sampling opening in the lowerportion. The weight of the copper-based catalyst precursor A included inthe diluted mixture was 26.5 g.

In a state in which the temperature of the catalyst layer was maintainedin a range of 200±5° C., the air was circulated at 12 L/hr for 1 hour.After that, the supply of the air was stopped, and nitrogen gas wascirculated at 137.5 L/hr for 1 hour so that the temperature of thecatalyst layer was maintained in a range of 200±5° C. After that, theflow rate of hydrogen gas was increased while the flow rate of nitrogengas was decreased so that the temperature of the catalyst layer wasmaintained in a range of 200±5° C., finally, the flow rate of hydrogengas was set to 6 L/hr, and the copper-based catalyst precursor A wasreduced over 1 hour.

After the reduction treatment, the supply of the hydrogen gas wasstopped, and nitrogen gas and 2,7-octadiene-1-ol were circulated at137.5 L/hr and 70.2 g/hr (0.558 mol/hr) respectively so that thetemperature of the catalyst layer was maintained in a range of 200±5° C.The reaction was caused at the atmospheric pressure for 3 hours, and thequantity of the product was determined through gas chromatography every30 minutes.

The conversion ratio of 2,7-octadiene-1-ol was computed using Equation 1described below. The unit of individual amounts in the equation is‘mol/hr’.The conversion ratio (%) of 2,7-octadiene-1-ol={(the amount of rawmaterials supplied−the amount of unreacted raw materials)/the amount ofraw materials supplied}×100  (Equation 1)

Examples of the respective products include 7-octenal,2,7-octadiene-1-al, 7-octene-1-ol, octadienes, cis- or trans-6-octenal,1-octanal, and 1-octanol. The selectivity into the above-describedproducts was computed using Equation 2 described below. The unit ofindividual amounts in the equation is ‘mol/hr’.The selectivity (%) of each product={the amount of each product/(theamount of raw materials supplied−the amount of unreacted rawmaterials)}×100  (Equation 2)

The selectivity into high-boiling point products, the quantities ofwhich could not be determined through gas chromatography, was computedusing Equation 3 described below. The unit of individual amounts in theequation is ‘mol/hr’.The selectivity (%) of the high-boiling point product=100−(the sum ofthe selectivity of individual products)  (Equation 3)

During 3 hours of the reaction, there was no large change in thereaction achievement, and thus the conversion ratio and selectivity werecomputed from the 3-hour average composition.

Assessment Example 2

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Bwas used, and the weight of the copper-based catalyst precursor Bincluded in the diluted mixture was set to 23.4 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Assessment Example 3

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Cwas used, and the weight of the copper-based catalyst precursor Cincluded in the diluted mixture was set to 26.5 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Assessment Example 4

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Dwas used, and the weight of the copper-based catalyst precursor Dincluded in the diluted mixture was set to 26.5 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Assessment Example 5

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Ewas used, and the weight of the copper-based catalyst precursor Eincluded in the diluted mixture was set to 21.4 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Assessment Example 6

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Fwas used, and the weight of the copper-based catalyst precursor Fincluded in the diluted mixture was set to 26.5 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Assessment Example 7

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Gwas used, and the weight of the copper-based catalyst precursor Gincluded in the diluted mixture was set to 26.5 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Comparative Assessment Example 1

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursorH1 was used, and the weight of the copper-based catalyst precursor H1included in the diluted mixture was set to 26.6 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Comparative Assessment Example 2

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursorH2 was used, and the weight of the copper-based catalyst precursor H2included in the diluted mixture was set to 26.0 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Comparative Assessment Example 3

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursorH3 was used, and the weight of the copper-based catalyst precursor H3included in the diluted mixture was set to 26.0 g. During 3 hours of thereaction, the conversion ratio of 2,7-octadiene-1-ol was decreased overtime. The conversion ratio became 65.3% immediately after the reaction,64.0% 1 hour after the reaction, 63.7% 2 hours after the reaction, and62.2% 3 hour after the reaction. The average value (63.8%) thereof wasused as the conversion ratio. Meanwhile, there was no large change inthe selectivity.

Comparative Assessment Example 4

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Iwas used, and the weight of the copper-based catalyst precursor Iincluded in the diluted mixture was set to 23.3 g. During 3 hours of thereaction, the conversion ratio of 2,7-octadiene-1-ol was decreased overtime. The conversion ratio became 50.1% immediately after the reaction,49.1% 1 hour after the reaction, 48.4% 2 hours after the reaction, and47.1% 3 hour after the reaction. The average value (48.7%) thereof wasused as the conversion ratio. Meanwhile, there was no large change inthe selectivity.

Comparative Assessment Example 5

An assessment was carried out in the same manner as in AssessmentExample 1 except for the fact that the copper-based catalyst precursor Jwas used, and the weight of the copper-based catalyst precursor Jincluded in the diluted mixture was set to 26.5 g. During 3 hours of thereaction, there was no large change in the reaction achievement, andthus the conversion ratio and selectivity were computed from the 3-houraverage composition.

Table 2 describes the isomerization reaction results of2,7-octadiene-1-ol as β,γ-unsaturated alcohol compounds for which thecopper-based catalyst obtained by reducing the copper-based catalystprecursors prepared in Examples 1 to 7 and Reference Examples 1 to 5were used (Assessment Examples 1 to 7 and Comparative AssessmentExamples 1 to 5).

The loading amounts in the table are the weights of the respectivecopper-based catalyst precursors included in 50 mL of the catalyst layerdiluted to 50% by mass using the soda glass beads having a diameter in arange of 3.962 mm to 4.699 mm.

7-octenal, 2,7-octadienal, 7-octene-1-ol, octadienes, cis- ortrans-6-octenal, 1-octanal, 1-octanol, and other high-boiling pointcompounds are referred to shortly as 7-OEL, ODL, OEA, OD, 6-OEL, OL, OA,and HB respectively.

TABLE 2 Copper- Load- Con- based ing version catalyst amount ratioSelectivity into various compounds (%) precursor (g) (%) 7-OEL ODL OEAOD 6-OEL OL OA HB Assessment A 26.5 96.4 81.5 9.8 4.7 1.0 1.3 1.3 0.20.2 Example 1 Assessment B 23.4 92.2 79.4 10.7 5.6 0.3 1.1 0.8 0.2 1.9Example 2 Assessment C 26.5 92.4 78.1 10.8 5.5 1.1 1.2 1.1 0.3 1.9Example 3 Assessment D 26.5 92.5 76.6 11.1 6.2 1.0 1.2 0.7 0.2 3.0Example 4 Assessment E 21.4 91.8 76.6 10.8 5.1 0.5 1.2 1.3 0.3 4.2Example 5 Assessment F 26.5 97.8 81.3 9.6 4.6 1.1 1.3 1.4 0.2 0.6Example 6 Assessment G 26.5 95.2 81.1 10.1 5.8 0.6 0.9 0.7 0.2 0.6Example 7 Comparative H1 26.6 82.3 75.8 10.8 5.1 1.3 1.3 1.6 0.3 3.8Assessment Example 1 Comparative H2 26.0 79.3 75.0 12.6 6.3 0.4 1.4 1.30.3 2.7 Assessment Example 2 Comparative H3 26.1 63.8 72.8 14.5 6.2 0.61.9 1.9 0.4 1.7 Assessment Example 3 Comparative I 23.3 48.7 73.5 14.87.5 0.6 1.2 0.9 0.4 1.1 Assessment Example 4 Comparative J 26.5 78.268.2 12.9 7.0 5.5 1.2 1.4 0.3 3.5 Assessment Example 5

The comparison between Assessment Examples 2 and 5 and ComparativeAssessment Example 4 exhibited a difference in the calcinationtemperature of the dried product of the same coprecipitated mixture, andin the copper-based catalyst precursor B calcined at 800° C., thecopper-based catalyst precursor E calcined at 600° C., and thecopper-based catalyst precursor I calcined at 400° C., a high conversionratio and high selectivity could be achieved only in a case in which thecopper-based catalyst precursor for which the calcination temperaturewas set to 600° C. or higher was used. The above-described improvementof the catalyst performance by the high-temperature calcination could beconfirmed even in a case in which the copper-based catalyst precursorsH1 to H3 to which γ-alumina was added were used (Comparative AssessmentExamples 1 to 3). However, according to the comparison betweenAssessment Example 2 and Comparative Assessment Example 1, a higherconversion ratio and a higher selectivity could be achieved when thecopper-based catalyst precursor B to which calcium silicate was addedwas used rather than the copper-based catalyst precursor H1 to whichγ-alumina was added.

According to the comparison between Assessment Example 3 and ComparativeAssessment Example 5, in the copper-based catalyst precursor J includingno iron, a high conversion ratio and high selectivity could not beachieved.

Particularly, when the copper-based catalyst precursors A, F, and G wereused, a higher conversion ratio and a higher selectivity could beachieved. Assessment Examples 1, 6, and 7 had almost the same Cu/Fe/Alatomic ratio as the copper-based catalyst precursor A, but had differentamount of calcium silicate.

The fact that sufficient performance can be achieved even by forming thecopper-based catalyst precursor of the present invention will bedescribed. A method for forming the copper-based catalyst precursor willbe described in Examples 8 and 9. In Assessment Examples 8 and 9,capabilities of a copper-based catalyst obtained by reducing the formedcopper-based catalyst precursor for isomerizing an aldehyde compoundfrom a compound having a β,γ-unsaturated alcohol portion, morespecifically, capabilities for isomerizing 7-octenal from2,7-octadiene-1-ol in the fixed-bed reaction method in which thecopper-based catalyst precursors prepared in Examples 8 and 9 are usedwill be described in more detail.

Example 8

The dried product of the coprecipitated mixture prepared under the sameconditions as in Example 1 was formed into a cylindrical shape having adiameter of 3 mm and a thickness of 3 mm using a rotary tablet formingmachine. The formed product was calcined in the air at 800° C. for 6hours, thereby obtaining a catalyst precursor K.

Example 9

The powder-form copper-based catalyst precursor prepared under the sameconditions as in Example 1 was formed into a cylindrical shape having adiameter of 3 mm and a thickness of 3 mm using a rotary tablet formingmachine. After that, the formed product was calcined at 500° C. for 1hour, thereby obtaining a catalyst precursor L.

Assessment Example 8

An assessment was carried out using the same method as in AssessmentExample 1 except for the fact that 50 mL of a mixture obtained bydiluting the catalyst precursor K to 50% by mass using soda glass beadshaving a diameter in a range of 3.962 mm to 4.699 mm was loaded. Themass of the copper-based catalyst precursor included in the dilutedmixture was set to 26.9 g.

During 3 hours of the reaction, there was no large change in thereaction achievement, and thus the conversion ratio and selectivity werecomputed from the 3-hour average composition.

Assessment Example 9

An assessment was carried out using the same method as in AssessmentExample 1 except for the fact that 50 mL of a mixture obtained bydiluting the catalyst precursor L to 50% by mass using soda glass beadshaving a diameter in a range of 3.962 mm to 4.699 mm was loaded. Themass of the copper-based catalyst precursor included in the dilutedmixture was set to 26.9 g.

During 3 hours of the reaction, there was no large change in thereaction achievement, and thus the conversion ratio and selectivity werecomputed from the 3-hour average composition.

In Assessment Examples 8 and 9 in Table 3, the isomerization reactionresults of 2,7-octadiene-1-ol as β,γ-unsaturated alcohol compounds forwhich the copper-based catalyst obtained by reducing the formedcopper-based catalyst precursors prepared in Examples 8 and 9 is usedare described. In addition, the result of Assessment Example 1 in whichthe powder-form copper-based catalyst precursor was used is alsodescribed for reference.

TABLE 3 Copper- Load- Con- based ing version catalyst Note ofcopper-based amount ratio Selectivity into various compounds (%)precursor catalyst precursor (g) (%) 7-OEL ODL OEA OD 6-OEL OL OA HBAssessment K Precursor obtained by molding the 26.9 80.1 81.0 9.1 5.21.9 1.2 1.4 0.2 — Example 8 dried raw powder of A and then calcining thepowder at 800° C. Assessment L Precursor obtained by molding 26.9 94.682.0 8.5 4.6 1.2 1.5 1.9 0.2 — Example 9 catalyst precursor A AssessmentA Powder-form copper-based catalyst 26.5 96.4 81.5 9.8 4.7 1.0 1.3 1.30.2 0.2 Example 1 precursor fired at 800° C.

As described in Assessment Examples 1 to 9, the copper-based catalystprecursor of the present invention can be used for the isomerization ofthe β,γ-unsaturated alcohol compound in both a powder state and a formedstate.

Assessment Example 10 Isomerization Reaction in the Presence of HydrogenGas and Nitrogen Gas

100 mL of the copper-based catalyst precursor L was loaded into anatmospheric pressure circulation-type stainless steel SUS316 verticalstraight reaction tube (inner diameter: 22 mm, length: 1 m) including anelectric heater for controlling the temperature of a catalyst layeroutside, a thermocouple for measuring the temperature of the catalystlayer inside, a gas supply opening in the upper portion, and a samplingopening in the lower portion.

In a state in which the temperature of the catalyst layer was maintainedin a range of 200±5° C., the air was circulated at 24 L/hr for 1 hour.After that, the supply of the air was stopped, and nitrogen gas wascirculated at 275.0 L/hr for 1 hour so that the temperature of thecatalyst layer was maintained in a range of 200±5° C. After that, theflow rate of hydrogen gas was increased while the flow rate of nitrogengas was decreased so that the temperature of the catalyst layer wasmaintained in a range of 200±5° C., finally, the flow rate of hydrogengas was set to 12 L/hr, and the copper-based catalyst precursor A wasreduced over 1 hour.

After the reduction treatment, the supply of the hydrogen gas wastemporarily stopped, and a gas mixture of 0.3% by volume of hydrogen and99.7% by volume of nitrogen and a liquid mixture of 30.4% by mass of7-octene-1-ol and 69.6% by mass of 2,7-octadiene-1-ol were respectivelysupplied at 101.8 L/hr and 53.1 g/hr so that the temperature of thecatalyst layer was maintained in a range of 200±5° C. The reaction wascaused at 0.145 MPa (G) for 4 hours.

During 4 hours of the reaction, there was no large change in thereaction achievement. The 4-hour average composition was 0.3% by mass of2,7-octadiene-1-ol, 79.6% by mass of 7-octenal, 0.1% by mass of2,7-octadienal, 15.3% by mass of 7-octene-1-ol, 0.2% by mass ofoctadienes, 0.1% by mass of cis- or trans-6-octenal, 3.5% by mass of1-octanal, 0.7% by mass of 1-octanol, and 0.2% by mass of otherhigh-boiling point compounds.

Comparative Assessment Example 6

An assessment was carried out using the same operation and the samemethod as in Assessment Example 10 except for the fact that 100 mL of“E26L” manufactured by JGC Catalysts and Chemicals Ltd. was used insteadof the use of 100 mL of the copper-based catalyst precursor L.

During 4 hours of the reaction, there was no large change in thereaction achievement. The 4-hour average composition was 0.3% by mass of2,7-octadiene-1-ol, 71.7% by mass of 7-octenal, 0.1% by mass of2,7-octadienal, 18.5% by mass of 7-octene-1-ol, 1.0% by mass ofoctadienes, 0.1% by mass of cis- or trans-6-octenal, 2.9% by mass of1-octanal, 0.7% by mass of 1-octanol, and 4.7% by mass of otherhigh-boiling point compounds.

As clarified from the comparison between Assessment Example 10 in whichthe copper-based catalyst precursor L was used and ComparativeAssessment Example 6 in which “E26L” was used, even in a case in whichthe isomerization reaction was caused in the co-presence of hydrogengas, the yield of 7-octenal became higher when the copper-based catalystprecursor L was used.

The copper-based catalyst precursor of the present invention can be usedfor the hydrogenation of a carbon-carbon double bond, the hydrogenationof a carbon-oxygen double bond, and the like which are the ordinary usesof the copper-based catalyst precursor. More specifically, in Examples10 and 11 described below, the hydrogenation reaction of 1-octanol from7-octenal in the slurry-bed reaction method in which the copper-basedcatalyst precursor was used will be described.

Example 10

0.3 g of the catalyst precursor A and 20 g of dehydrated and distilled1,4-dioxane were put in a 100 mL SUS316 autoclave, were substituted bynitrogen, and were put at the atmospheric pressure. After that, in astate in which the components were sufficiently stirred, the catalystprecursor A was reduced for 30 minutes in a state of 180° C. and ahydrogen pressure of 10 MPa (G). While this state is maintained, 40 g(0.317 mol) of 7-octenal was sent by pressure, and a reaction wasinitiated.

The amount of the product after 5 hours of the reaction was determinedthrough gas chromatography. After 5 hours of the reaction, the amount of7-octenal was equal to or less than the detection capability, and as theproducts, only 7-octene-1-ol and 1-octanol can be detected. The yieldsof these products were computed using Formula 4 described below. Theunits of the respective amounts in the formula are “mol”.Yield (%) of each product=(the amount of each product/introduced7-octenal)×100  (Equation 4)

The yield of 7-octene-1-ol after 5 hours of the reaction was 2.4%, andthe yield of 1-octanol was 97.6%.

Example 11

The same reaction was caused as in Example 10 except for the fact that0.3 g of the catalyst precursor B was used. After 5 hours of thereaction, the amount of 7-octenal was equal to or less than thedetection capability, and the yield of 7-octene-1-ol was 6.4%, and theyield of 1-octanol was 93.6%.

As described in Examples 10 and 11, the copper-based catalyst precursorof the present invention can be used even for the hydrogenation of acarbon-carbon double bond and a carbon-oxygen double bond.

The copper-based catalyst precursor of the present invention can be usedfor the hydrogenation of ketone compounds having a carbon-oxygen doublebond. More specifically, in Example 12 described below, thehydrogenation reaction of 4-methyl-2-pentanol from 4-methyl-2-pentanonein the slurry-bed reaction method in which the copper-based catalystprecursor was used will be described.

Example 12

A reaction was caused using the same method as in Example 10 except forthe fact that 40 g (0.399 mol) of 4-methyl-2-pentanone was used insteadof 7-octenal. After 40 minutes, the reaction liquid contained 40.31 g of4-methyl-2-pentanol, and the yield thereof was 98.8%.

As described in Example 12, the copper-based catalyst precursor of thepresent invention can also be used for the hydrogenation of ketonecompounds having a carbon-oxygen double bond.

INDUSTRIAL APPLICABILITY

The copper-based catalyst precursor of the present invention is usefulas a catalyst for the reaction of a compound having a β,γ-unsaturatedalcohol portion for isomerizing the β,γ-unsaturated alcohol portion toan aldehyde group. For example, 7-octenal obtained by isomerizing2,7-octadiene-1-ol using the copper-based catalyst precursor is acompound having a highly reactive terminal double bond and an aldehydegroup, and is useful as a raw material for a variety of industrialchemicals. Specifically, 1,9-nonanedial can be produced byhydroformylating 7-octenal, and furthermore, it is possible to obtain1,9-nonanediamine which is useful as a macromolecular monomer rawmaterial through a reductive amination reaction.

Furthermore, the copper-based catalyst precursor of the presentinvention is also useful as a hydrogenation catalyst for compoundshaving either or both a carbon-carbon double bond and a carbon-oxygendouble bond. Particularly, 1-octanol obtained through the hydrogenationreaction of 7-octenal is useful as a resin plasticizer.

The invention claimed is:
 1. A copper-based catalyst precursor, obtainedby a process comprising: calcining a mixture comprising copper, iron,aluminum, and calcium silicate, wherein an atomic ratio of iron andaluminum to copper [(Fe+Al)/Cu] is in a range of from 1.71 to 2.5, anatomic ratio of aluminum to iron [Al/Fe] is in a range of from 0.001 to3.3, and the mixture comprises calcium silicate in a range of from 15%by mass to 65% by mass at a temperature of from 500° C. to 1,000° C. 2.The copper-based catalyst precursor according to claim 1, wherein themixture is a dried product of a coprecipitated mixture obtained by aprocess comprising: mixing a coprecipitate and calcium silicate, and thecoprecipitate is obtained by reacting a mixed aqueous solutioncomprising a water-soluble copper salt, a water-soluble iron salt, and awater-soluble aluminum salt with a basic aqueous solution.
 3. Thecopper-based catalyst precursor according to claim 1, wherein, in thecalcium silicate, an atomic ratio of silicon to calcium [Si/Ca] is in arange of from 0.5 to 6.5.
 4. The copper-based catalyst precursoraccording to claim 2, wherein a BET specific surface area of the mixtureis in a range of from 50 m²/g to 250 m²/g.
 5. The copper-based catalystprecursor according to claim 1, wherein the calcium silicate is aGyrolite-type synthetic calcium silicate represented by2CaO.3SiO₂.mSiO₂.nH₂O where m and n, respectively, are numberssatisfying 1<m<2 and 2<n<3.
 6. The copper-based catalyst precursoraccording to claim 5, wherein a bulk specific volume of the calciumsilicate is 4 mL/g or more.
 7. A copper-based catalyst obtained by aprocess comprising: reducing the copper-based catalyst precursoraccording to claim
 1. 8. A method for producing the copper-basedcatalyst precursor according to claim 1, the method comprising: reactinga mixed aqueous solution comprising a water-soluble copper salt, awater-soluble iron salt, and a water-soluble aluminum salt with a basicaqueous solution to obtain a coprecipitate comprising copper, iron, andaluminum; adding calcium silicate to a suspension comprising thecoprecipitate suspended in water and mixing calcium silicate and thesuspension to obtain a coprecipitated mixture; separating thecoprecipitated mixture, washing the coprecipitated mixture with water,and then drying the coprecipitated mixture, thereby obtaining a driedproduct of the coprecipitated mixture; and calcining the dried productof the coprecipitated mixture at a calcination temperature of from 500°C. to 1,000° C.
 9. The method according to claim 8, wherein, in saidreacting, a reaction temperature is in a range of from 5° C. to 150° C.,and a pH of the aqueous solution is in a range of from 6.0 to 13.5, andin said adding, calcium silicate is added to the suspension at atemperature of from 5° C. to 100° C., and a pH of the suspension is in arange of from 7 to
 9. 10. The method according to claim 8, wherein, insaid reacting, the water-soluble copper salt is copper (II) sulfate, thewater-soluble iron salt is iron (I) sulfate, and the water-solublealuminum salt is aluminum sulfate.
 11. The method according to claim 8,wherein the calcination temperature in said calcining is in a range offrom 600° C. to 900° C.
 12. A hydrogenation method of a compoundcomprising at least one of a carbon-carbon double bond and acarbon-oxygen double bond, the method comprising: employing thecopper-based catalyst precursor according to claim 1 in the method. 13.The hydrogenation method according to claim 12, wherein the method iscarried out at a temperature of from 100° C. to 300° C. and at a totalpressure of from 0.01 MPa(G) to 30 MPa(G).
 14. The hydrogenation methodaccording to claim 12, wherein the method is carried out using aslurry-bed reaction method.
 15. The hydrogenation method according toclaim 12, wherein the compound comprising at least one of acarbon-carbon double bond and a carbon-oxygen double bond is selectedfrom the group consisting of an aldehyde which optionally comprises acarbon-carbon double bond, a ketone which optionally comprises acarbon-carbon double bond, a carboxylic acid which optionally comprisesa carbon-carbon double bond, an ester which optionally comprises acarbon-carbon double bond, an acid anhydride which optionally comprisesa carbon-carbon double bond, and a sugar which optionally comprises acarbon-carbon double bond.